Compressor with controlled capacity

The application claims the priority of the Chinese patent application No. 200510028385.X with filing date of Aug. 2, 2005.

1. Field of the Invention

The present invention relates to a rotatable compressor used for air conditioner, refrigerator and hot-pump type water heater, and more particularly to a compressor with controlled capacity and its capacity switch device.

2. Description of Related Art

The conventional compressor with controlled capacity is generally provided with openings in communication with intake and discharge chamber at single stage compressor cylinder or its upper or lower cylinder head, the open and cut-off of the openings is controlled by means of solenoid valve to realize the capacity control, also, there are two or more compressors connected in parallel to effect the capacity control. The capacity controlling way of this type is technically complex, less reliability and high overall cost.

The object of the present invention is to provide a compressor with controlled capacity, the flow of refrigerant gas in the double cylinder compressor is changed through a capacity switch device to realize the conversion between compression in series or in parallel of the double cylinders, as a result, the compressor outputs discharge capacity of one cylinder or two cylinders.

The another object of the present invention is to provide a 4way-2way solenoid valve suitable for the above mentioned compressor with controlled capacity, in order to simplify the structure and control of the said type compressor.

A compressor with controlled capacity in accordance with the invention mainly includes a double cylinder compressor with a reservoir, a capacity switch device, the outlet for the intake pipe of the said reservoir is divided into two branches, which are connected with the upper and lower cylinder through a capacity switch device switched between the 2way-2through and oneway-2through switch to realize the connection in series or in parallel for the double cylinder, as a result, the discharge capacity is the discharge capacity of the first stage cylinder when connection in series, or the sum of the two cylinders discharge when connection in parallel.

The capacity switch device has two input passages a and c and two output passages b and d, while in one work state, the input passage a is communicated with the output passage b, the input passage c is communicated with the output passage d; however in the other work state after switching, one passage between the input passage c and the output passage b or between the input passage a and the output passage d is blocked.

The special 4way-2way solenoid valve used in the compressor with controlled capacity in accordance with the invention has a pneumatic slide valve controlled by a solenoid valve, the said slide valve mainly includes a movable valve core controlled by a solenoid valve, a valve seat and two input passages and two output passages, the middle of the said valve core is a gas collection chamber which has 4 passages, one of which is an input passage a and the other three passages arranged equidistantly on the valve seat, the left and right one are output passage b, d, the middle one is another input passage c; the valve core drives a throttle bowl which can slide on the valve seat towards left or right, on the left or right position can cover the throttle bowl the left adjacent 2 passages b, c, or the right adjacent 2 passages c, d and make them in communication; at the same time the input passage a is communicated with the output passage d or c which is not covered by the throttle bowl, characterized in that the throttle bowl is provided with a bowl tongue on one side, when the throttle bowl is situated on one position and only on this position, the bowl tongue covers and blocks the output passage on the seat which is not covered by the throttle bowl.

The advantage of the present invention consists in that it may conveniently realize the conversion between two stage compressor and double cylinder compressor to complete the control of two discharge volume by making use of the said capacity switch device, particularly the special 4way-2way solenoid valve in connection with a double cylinder compressor in accordance with the present invention, this may not only reduce the manufacture cost but also simplify the fabrication process and reduce the installation space for the compressor, furthermore the control is very simple and reliable so that the market competence is raised significantly.

FIG. 1 is the structural diagram for the first embodiment of the present invention,

FIG. 2 is the structural diagram for the second embodiment of the present invention,

FIG. 3 is a sketch diagram of a capacity switch device which is switched between 2way-2through and 1way-2through,

FIG. 4 is a sketch diagram of the special 4way-2way solenoid valve in accordance with the present invention,

FIG. 5 is a sketch diagram of a capacity switch device consisted of a single way valve and a 4way valve,

FIG. 6 is a sketch diagram of a capacity switch device consisted of a solenoid valve and a 4way valve,

FIG. 7 is a sketch diagram of a capacity switch device consisted of three solenoid valves,

FIG. 8 is a sketch diagram of a capacity switch device consisted of a single way valve and a solenoid valve.

In the drawings there are shown the reservoir outlet 12 , 14 , lower cylinder 20 , intake inlet of the lower cylinder 22 , discharge outlet of the lower cylinder 24 , upper cylinder 30 , intake inlet of the upper cylinder 32 , discharge outlet of the upper cylinder 34 , compressor casing 40 , upper outlet of the casing 42 , bypass of the casing 44 , branch pipe 46 , reversing valve 50 , solenoid valve 51 , input passage a 52 , slide valve 53 , valve core 532 , gas collection chamber 534 , valve seat 536 , valve bowl 538 , output passage b 54 (unblocked), input passage c 56 , output passage d 58 (blocked), single way valve M and solenoid valve N.

The present invention is described in more detailed with respect to several embodiments.

The present embodiment shows the connection form between a double cylinder compressor and the special 4way-2way reversing valve according to the invention as shown in FIG. 1 . An outlet 12 of the reservoir 10 is connected with inlet 22 of the lower cylinder, the outlet 24 of the lower cylinder is connected with the unblocked output passage 54 of the reversing valve 50 , the input passage 52 of the reversing valve is connected with the bypass 44 on the compressor casing; the another outlet 14 of the reservoir is connected with the output passage 58 of the reversing valve which may be blocked, the input passage 56 of the reversing valve is connected with the inlet 32 of the upper cylinder, the gas compressed by the upper cylinder will be discharged through the compressor upper outlet 42 .

The work process is performed as follows: when the reversing valve is in the 2way-2through state, the fluid in one passage 12 of the reservoir enters the lower cylinder 20 , the output of the lower cylinder 20 enters the bypass 44 on the compressor casing through the passage 54 - 52 of the reversing valve, the fluid in another passage 14 of the reservoir enters the upper cylinder 30 through the passage 58 - 56 of the reversing valve, the output of the upper cylinder 30 and the output of the lower cylinder 20 converge in the compressor casing, and discharged through the upper outlet 42 on the compressor casing. At this time the two cylinders are arranged in parallel, the discharge volume is the sum of the two cylinders' discharge amount.

When the reversing valve is in the oneway-2through state, the output of the lower cylinder 20 enters the upper cylinder 30 through the passage 54 - 56 of the reversing valve, the output of the upper cylinder 30 is discharged through the upper outlet 42 on the compressor casing, the fluid in another passage 14 of the reservoir is blocked at the output passage 58 of the reversing valve which may be blocked, at this time this passage is inactive.

This connection form is characterized in that when two cylinders are arranged in series, the discharged amount is that of the first stage cylinder, and the gas in the casing is the high pressure gas discharged from the second stage cylinder.

The present embodiment shows another connection form between a double cylinder compressor and the special 4way-2way reversing valve according to the invention as shown in FIG. 2 . An outlet 12 of the reservoir 10 is connected with inlet 22 of the lower cylinder, the outlet 24 of the lower cylinder is discharged into the compressor casing and connected with the unblocked output passage 54 of the reversing valve through the upper outlet 42 on the compressor casing; the another outlet 14 of the reservoir is connected with the output passage 58 of the reversing valve which may be blocked, the input passage 56 of the reversing valve is connected with the inlet 32 of the upper cylinder, the output 34 of the upper cylinder is the output of the compressor, at the same time, connected with the input passage 52 of the reversing valve through a branch pipe 46 on the casing.

The work process is performed as follows: when the reversing valve is in the 2way-2through state, the fluid in one passage 12 of the reservoir enters the lower cylinder 20 , the output 24 of the lower cylinder 20 is discharged into the compressor casing and enters the branch pipe 46 through the upper outlet 42 on the compressor casing and the passage 54 - 52 of the reversing valve, the fluid in another passage 14 of the reservoir enters the upper cylinder 30 through the passage 58 - 56 of the reversing valve, the output 34 of the upper cylinder 30 and the output of the lower cylinder 20 from the branch pipe converge as the compressor output. At this time the two cylinders are arranged in parallel, the discharge volume is the sum of the two cylinders' discharge amount.

When the reversing valve is in the oneway-2through state, the output 24 of the lower cylinder 20 is discharged into the compressor casing and enters the upper cylinder 30 through the upper outlet 42 and the passage 54 - 56 of the reversing valve, the output 34 of the upper cylinder 30 is discharged as the compressor output; the fluid in another passage 14 of the reservoir is blocked at the output passage 58 of the reversing valve which may be blocked, at this time the branch pipe 46 connected with the output 34 of the upper cylinder 30 is also blocked at the output passage 58 of the reversing valve which may be blocked. At this time the two cylinders are arranged in series, the discharge volume is that of the first stage cylinder.

This connection form is characterized in that when two cylinders are arranged and compressed in series, the middle pressure gas in the casing is discharged from the first stage cylinder, it is advantageous to reduce the pressure sustaining requirement of the casing and prevent the leakage of the refrigerant.

The capacity switch device may be a 4way-2way reversing valve as shown in FIG. 3 . The reversing valve has two input passages a and c and two output passages b and d, while in one work state, the input passage a is communicated with the output passage b, the input passage c is communicated with the output passage d; however in the other work state after switching, the input passage c is communicated with the output passage b, the input passage a and the output passage d are blocked.

Based on the work principle of the said capacity switch device as shown in FIG. 3 , the device may consist of a single way valve M and a general 4way valve as shown in FIG. 5 , the single way valve M is provided in one output passage of the general 4way valve in series, when gas flows from this output passage to the 4way valve, the flow is blocked so that one of the two passages is blocked as the 4way valve in one state.

Based on the work principle of the said capacity switch device as shown in FIG. 3 , the device may consist of a solenoid valve N and a general 4way valve as shown in FIG. 6 , the solenoid valve N is provided in one output passage of the general 4way valve in series. When the solenoid valve is switched on, the 4way valve is in 4way open state; when the solenoid valve is switched off, one of the two passages is blocked.

Based on the work principle of the said capacity switch device as shown in FIG. 3 , the device may consist of three solenoid valves as shown in FIG. 7 . The three solenoid valves N 1 ,N 2 ,N 3 are provided in series in such way that the free end of N 1 is input passage a, the connection point of N 1 and N 2 is output passage b, the connection point of N 2 and N 3 is another input passage c, the free end of N 3 is another output passage d. When the solenoid valve N 1 and N 3 are switched on while N 2 is switched off, the input passage a is in communication with the output passage b, and the input passage c is in communication with the output passage d; When the solenoid valve N 1 and N 3 are switched off while N 2 is switched on, the input passage c is in communication with the output passage b, and the other passages are blocked. Therefore it is possible to realize the switch function for the capacity switch device by controlling each solenoid valve.

Based on the work principle of the said capacity switch device as shown in FIG. 3 , the device may consist of a single way valve and two solenoid valves as shown in FIG. 8 . One single way valve M 1 and two solenoid valves N 4 , N 5 are provided in series in such way that the one end of M 1 is input passage a, the connection point of M 1 and N 4 is output passage b, the connection point of N 4 and N 5 is another input passage c, the other end of N 5 is output passage d. When the solenoid valve N 5 is switched on while N 4 is switched off, the input passage a is in communication with the output passage b, and the input passage c is in communication with the output passage d; when the solenoid valve N 4 is switched on while N 5 is switched off, the input passage c is in communication with the output passage b, and the passage between the input passage c and the output passage d is blocked, and so the passage between b and a is also blocked conversely. Therefore it is possible to realize the switch function for the capacity switch device by controlling the solenoid valve N 4 and N 5 .

One example of the special 4way-2way solenoid reversing valve used for the compressor with controlled capacity according to the present invention is shown in FIG. 4 . In the valve casing there are a solenoid valve 51 and a pneumatic slide valve 53 controlled by this solenoid valve; the said slide valve 53 mainly includes a movable valve core 532 controlled by a solenoid valve, a valve seat 536 and two input passages and two output passages; the middle valve core is gas collection chamber 534 which has four passages, one of which is served as input passage 52 , the other passages are equidistantly arranged on the valve seat 536 , the left and right passage are two output passages 54 and 58 , the middle one is another input passage 56 ; the said valve core 532 drives a bowl valve 538 which may slide in left or right direction on the seat 536 , the bowl valve can cover the two adjacent passages 54 or 56 on the left side, or the two adjacent passages 56 or 58 on the right side of the valve seat 536 at left and right position respectively, and make them in communication; the said bowl valve 538 is provided with a bowl valve tongue 538 a on the right side, when the bowl valve 538 is on the right side, the bowl valve 538 covers the two adjacent passages 56 and 58 on the right side of the valve seat 536 , the bowl valve tongue 538 a a is inactive; when the bowl valve 538 is on the left side, the bowl valve 538 covers the two adjacent passages 54 and 56 on the left side of the valve seat 536 , the other output passage 58 is blocked by the bowl valve tongue 538 a ; one of the two output passages is blocked.

Evidently the bowl valve tongue 538 a may be provided on the left side of the bowl valve 538 as well, at this point it is the output passage 54 on the left side of the valve seat 536 that is blocked, and the work principle is similar.