Piston variable displacement compressor of automobile air conditioner

Abstract

The automobile air conditioner piston variable displacement compressor comprises a clutch, a front cover, a cylinder body and a rear cover, a swash plate cavity is formed between the front cover and the cylinder body, a main shaft connected with the clutch is arranged in the cylinder body, a refrigeration oil channel extending in the axial direction of the main shaft is arranged in the center of the main shaft, and a transverse hole communicating the refrigeration oil channel with the swash plate cavity is formed in the wall face of the main shaft. A switch valve is arranged in the end, close to the clutch, in the refrigeration oil channel and comprises a spring and a valve element, the circumferential direction of the valve element is in sliding sealing fit with the wall face of the refrigeration oil channel, one end of the spring is fixed to the end, close to the clutch, of the refrigeration oil channel, and the other end of the spring is connected with the valve element. The blocking piece comprises a blocking piece extending into the refrigeration oil channel from the transverse hole, a gap is formed between the edge of the blocking piece and the refrigeration oil channel, and the blocking piece is matched with the valve element in a blocking mode. The switch valve is additionally arranged on the main shaft, when an air conditioner is turned off, the valve element of the switch valve blocks the transverse hole in the main shaft, and refrigerant oil is prevented from entering an air suction and exhaust cavity of the compressor.

Description

Technical Field

[0001] The invention relates to a variable displacement piston compressor for an automobile air conditioner, belonging to the technical field of automobile air conditioner compressors. Background Art

[0002] During long-distance transportation, the temperature of the piston air-conditioning compressor for automobiles changes during the day and night, resulting in a temperature difference between the inside and outside of the car. The mixture of the refrigerant oil and R134a refrigerant in the compressor will undergo a natural phenomenon of oil migration under the action of the temperature difference. Figure 1 At night, the refrigerant and refrigeration oil in a low-temperature liquid state flow to the evaporator and condenser; during the day, as the cab temperature rises, the evaporator temperature rises, and only the refrigerant gas with a higher temperature can flow out of the evaporator and condenser to the compressor, while the refrigeration oil remains in the evaporator and condenser.

[0003] According to the above natural change phenomenon, when the compressor is transported long distances with the whole vehicle, the refrigerant oil inside the compressor will flow out of the compressor in large quantities. This problem is particularly obvious in areas with large temperature differences between day and night (such as the Middle East, South America, Africa, etc.). Refrigerant oil is an important lubricant for the internal operation of the compressor. Running in a state of oil shortage or even without oil will cause irreversible damage to the compressor.

[0004] For fixed-displacement compressors: Since the suction chamber is directly connected to the swash plate chamber of the mechanism movement, after the air conditioner is turned on, the refrigerant oil inside the air-conditioning system can quickly flow back to the swash plate chamber of the compressor to lubricate the moving mechanism. Therefore, there is basically no problem of compressor damage caused by long-term dry grinding without oil / lack of oil.

[0005] For variable displacement compressors: Since the suction cavity is not directly connected to the swash plate cavity of the mechanism movement, after the air conditioner is turned on, the refrigerant oil inside the air conditioning system needs to run for a certain period of time before it can flow back into the swash plate cavity. During this period, the movement mechanism is prone to irreversible damage due to lack of oil, thus affecting the service life of the compressor. At present, there is no effective containment or solution to the oil migration problem of this variable displacement compressor. Summary of the invention

[0006] The object of the present invention is to provide a variable displacement piston compressor for an automobile air conditioner, which can avoid oil migration in an environment with a large temperature difference between day and night, thereby protecting the normal operation of the variable displacement compressor.

[0007] The present invention adopts the following technical scheme: a piston variable displacement compressor for automobile air conditioner, comprising a clutch, a front cover, a cylinder body, and a rear cover, wherein a swash plate cavity is provided between the front cover and the cylinder body, a main shaft connected to the clutch is provided in the cylinder body, a refrigeration oil passage extending along the axial direction of the main shaft is provided at the center of the main shaft, a transverse hole connecting the refrigeration oil passage and the swash plate cavity is provided on the wall surface of the main shaft, a switch valve is provided in one end of the refrigeration oil passage close to the clutch, the switch valve comprises a spring and a valve core, the circumference of the valve core is in sliding sealing cooperation with the wall surface of the refrigeration oil passage, one end of the spring is fixed on the refrigeration oil passage, and the refrigeration oil passage is provided with a swash plate cavity. One end of the refrigerated oil channel is close to the clutch, and the other end is connected to the valve core. A stopper is fixed in the transverse hole. The stopper includes a baffle extending from the transverse hole to the refrigerated oil channel. There is a gap between the edge of the baffle and the refrigerated oil channel. The baffle cooperates with the valve core to stop. When the compressor is in a non-working state, under the action of the spring force, the valve core seals on the baffle, and the valve core blocks the transverse hole; when the compressor is running, under the action of the electromagnetic force of the clutch, the valve core moves toward the clutch, the spring is compressed, the valve core is separated from the baffle, and the transverse hole is opened to communicate with the refrigerated oil channel.

[0008] The end of the refrigeration oil channel close to the clutch is a tapered hole, and the spring is fixed in the tapered hole.

[0009] The valve core is a cylindrical structure with one end open and the other end closed. The spring is connected inside the valve core, and the closed end of the valve core is in sealing contact with the baffle.

[0010] The surfaces where the closed end of the valve core contacts the baffle are both planes.

[0011] The stopper comprises a bushing fixed in the transverse hole, and the stopper is fixedly connected to the bushing.

[0012] Beneficial effects of the present invention: After the present invention adds a switch valve on the main shaft, when the air conditioner is turned off, the valve core of the switch valve blocks the transverse hole on the main shaft to prevent the refrigeration oil from entering the compressor suction and exhaust chamber through the refrigeration oil channel, thereby effectively avoiding the oil migration problem, thereby effectively reducing the oil migration phenomenon when the compressor is transported long distances with the whole vehicle to areas with large temperature differences between day and night, and improving the service life of the compressor. When the air conditioner is turned on, the valve core of the switch valve moves toward the clutch under the action of electromagnetic force, so that the transverse hole on the main shaft opens to ensure that the compressor can work normally. The present invention solves the oil migration problem of the variable displacement compressor in the prior art and extends the service life of the compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the flow of refrigeration oil in the air conditioning system at night and during the day; Figure 2 It is an appearance diagram of a piston variable displacement compressor for an automobile air conditioner according to an embodiment of the present invention; Figure 3 yes Figure 2A cross-sectional view of Figure 4 yes Figure 2 Schematic diagram without the switch valve; Figure 5 yes Figure 3 The enlarged view of point A in the middle (when the air conditioner is not working); Figure 6 This is the electromagnetic field distribution diagram when the air conditioner is working; Figure 7 yes Figure 3 Enlarged view of point A in the middle (when the air conditioner is working).

[0014] In the figure: 1-clutch, 2-front cover, 3-cylinder body, 4-rear cover, 5-oil drain bolt hole, 6-intake port, 7-exhaust port, 8-main shaft, 9-slant plate cavity, 10-intake and exhaust cavity, 11-refrigeration oil channel, 11.1-transverse hole, 12-switch valve, 12.1-spring, 12.2-valve core, 13-stopper, 13.1-blocking plate, 13.2-bushing. DETAILED DESCRIPTION

[0015] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0016] like Figures 2 to 7 As shown, an automobile air-conditioning piston variable displacement compressor according to an embodiment of the present invention comprises a clutch 1, a front cover 2, a cylinder body 3, and a rear cover 4, wherein a swash plate cavity 9 is provided between the front cover 2 and the cylinder body 3, a main shaft 8 connected to the clutch 1 is provided in the cylinder body 3, a refrigerant oil passage 11 extending axially along the main shaft 8 is provided at the center of the main shaft 8, and a transverse hole 11.1 connecting the refrigerant oil passage 11 and the swash plate cavity 9 is provided on the wall surface of the main shaft 8.

[0017] The front cover 2 and the cylinder body 3 form a swash plate cavity 9, the cylinder body 3 and the rear cover 4 form an intake and exhaust cavity 10, the front cover 2 is provided with an oil drain bolt hole 5, and the compressor is filled with refrigeration oil at the oil drain bolt hole 5, the intake port 6 and the exhaust port 7 are arranged on the rear cover 4, which are connected to the system and perform intake and exhaust actions.

[0018] A switch valve 12 is provided in one end of the refrigerant oil passage 11 near the clutch 1, and the switch valve 12 includes a spring 12.1 and a valve core 12.2. The valve core 12.2 is circumferentially matched with the wall of the refrigerant oil passage for sliding sealing. One end of the spring 12.1 is fixed to one end of the refrigerant oil passage 11 near the clutch 1, and the other end is connected to the valve core 12.2. A stopper 13 is fixed in the transverse hole, and the stopper 13 includes a stopper 13.1 extending from the transverse hole to the refrigerant oil passage 11, and the edge of the stopper 13.1 is in contact with the refrigerant oil passage. There is a gap between the channels 11, and the baffle 13.1 is matched with the valve core 12.2 for blocking. When the compressor is not in operation, under the elastic force of the spring 12.1, the valve core 12.2 is sealed against the baffle 13.1, and the valve core 12.2 blocks the transverse hole 11.1; when the compressor is running, under the electromagnetic force of the clutch 1, the valve core 12.2 moves toward the clutch 1, the spring 12.1 is compressed, the valve core 12.2 is separated from the baffle 13.1, and the transverse hole 11.1 is opened and communicated with the refrigeration oil channel 11. The end of the refrigeration oil channel 11 close to the clutch 1 is a tapered hole, and the spring 12.1 is fixed in the tapered hole.

[0019] The valve core 12.2 is a cylindrical structure with one end open and the other end closed. The spring 12.1 is connected to the inside of the valve core 12.2. The closed end of the valve core 12.2 is in sealing contact with the baffle 13.1. The surfaces where the closed end of the valve core 12.2 and the baffle 13.1 contact each other are both flat. The stopper 13 includes a bushing 13.2 fixed in the transverse hole, and the baffle 13.1 is fixedly connected to the bushing 13.2.

[0020] In the initial state, the refrigeration oil is completely filled into the swash plate cavity 9 through the oil discharge bolt hole 5. When oil migration occurs, the refrigeration oil in the swash plate cavity 9 mainly enters the air intake and exhaust cavity 10 and the evaporator and condenser from the refrigeration oil channel 11 in the main shaft 8. Since this gas path is also a key gas path for controlling the angle change of the variable displacement compressor, the present invention adds a switch valve 12 inside the main shaft. When the air conditioner is turned off, the switch valve 12 is also closed at the same time; when the air conditioner is turned on, the switch valve 12 is also opened at the same time. In this way, the purpose of preventing the refrigeration oil inside the compressor from flowing out into the air intake and exhaust cavity 10 and ensuring that the compressor can work normally can be achieved.

[0021] The working process and principle of the present invention are as follows: the spring 12.1 is installed in the position of the refrigerant oil channel 11 close to the clutch 1, the valve core 12.2 is connected to the spring, the bushing 13.2 is pressed into the transverse hole of the main shaft 8, and the tail of the bushing 13.2 has a small limit plane (i.e., the baffle 13.1), such as Figure 5As shown in the figure, when the air conditioner is not running, the valve core 12.2 moves along the refrigerant oil channel 11 under the elastic force of the spring 12.1 until it hits the limit surface at the tail of the bushing 13.2. At this time, the main shaft cross hole is completely blocked by the valve core 12.2, so the refrigerant oil in the swash plate cavity 9 will not enter the suction and exhaust cavity and the air conditioning system, and will still remain inside the compressor swash plate cavity 9. When the air conditioner is running, the magnetic field of the compressor clutch is as shown in Figure 6 As shown, under the electromagnetic force of the clutch 1, the valve core 12.2 offsets the elastic force of the spring and moves to the left, so that the transverse hole of the main shaft 8 is normally opened (as shown in FIG. Figure 7 As shown in the figure, the refrigeration oil flows out from the refrigeration oil channel 11 into the suction and exhaust chamber 10, so that the compressor gas circuit can flow normally and realize the function of normal variable displacement.

[0022] Compared with the prior art, the present invention avoids the problem of compressor oil migration in long-distance transportation and when the temperature difference between day and night is large by adding a switch valve in the main shaft, thereby effectively reducing the risk of damage to the service life of the compressor.

[0023] Although the above content has described the embodiments of the present invention in detail, the present invention is not limited to the above embodiments. The scope of the present invention defined by the appended claims includes all equivalent substitutions and changes.

Claims

1. A variable displacement piston compressor for automobile air conditioner, comprising a clutch, a front cover, a cylinder body, and a rear cover, wherein a swash plate cavity is provided between the front cover and the cylinder body, a main shaft connected to the clutch is provided in the cylinder body, a refrigeration oil passage extending along the axial direction of the main shaft is provided at the center of the main shaft, and a transverse hole connecting the refrigeration oil passage and the swash plate cavity is provided on the wall surface of the main shaft, characterized in that: A switch valve is provided in the end of the refrigerant oil channel close to the clutch, and the switch valve includes a spring and a valve core. The circumference of the valve core is in sliding sealing cooperation with the wall of the refrigerant oil channel. One end of the spring is fixed to the end of the refrigerant oil channel close to the clutch, and the other end is connected to the valve core. A stopper is fixed in the transverse hole, and the stopper includes a baffle extending from the transverse hole to the refrigerant oil channel, and there is a gap between the edge of the baffle and the refrigerant oil channel. The baffle and the valve core are in stop cooperation. When the compressor is in a non-working state, under the action of the spring elastic force, the valve core is sealed on the baffle, and the valve core blocks the transverse hole; when the compressor is running, under the action of the electromagnetic force of the clutch, the valve core moves toward the clutch, the spring is compressed, the valve core is separated from the baffle, and the transverse hole is opened to communicate with the refrigerant oil channel.

2. The automobile air-conditioning piston variable displacement compressor according to claim 1, characterized in that: The end of the refrigeration oil channel close to the clutch is a tapered hole, and the spring is fixed in the tapered hole.

3. The automobile air-conditioning piston variable displacement compressor according to claim 1, characterized in that: The valve core is a cylindrical structure with one end open and the other end closed. The spring is connected inside the valve core, and the closed end of the valve core is in sealing contact with the baffle.

4. The automobile air-conditioning piston variable displacement compressor according to claim 3, characterized in that: The surfaces where the closed end of the valve core contacts the baffle are both planes.

5. The automobile air-conditioning piston variable displacement compressor according to claim 1, characterized in that: The stopper comprises a bushing fixed in the transverse hole, and the stopper is fixedly connected to the bushing.

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