JP4966906B2 - Swash plate compressor - Google Patents

Description

  The present invention relates to a swash plate compressor.

  Patent Literature 1 describes “vehicle air conditioning control device”, and Patent Literature 2 describes “air conditioning device and variable displacement compressor control valve”.

  In the prior art of Patent Document 1, for example, when the vehicle cuts fuel to improve fuel efficiency during idling or deceleration, the compressor for air conditioning is controlled so as to minimize the discharge amount.

The variable displacement compressor of Patent Document 2 is a swash plate compressor, and the discharge amount of the swash plate compressor is controlled by changing the swing angle of the swash plate, and the swing angle is adjusted in the discharge chamber. This is done by feeding back the discharged high-pressure refrigerant to the swash plate chamber (crank chamber) by means of a capacity control valve. To prevent excessive pressure from being applied to the crank chamber by the refrigerant flowing back from the system side, A check valve is arranged between the two.
JP 2002-337542 A Japanese Patent No. 3780784

  In order to effectively improve fuel efficiency, it is necessary to quickly minimize the discharge amount, and in a swash plate compressor, high-pressure refrigerant is introduced into the crank chamber in a short time. Under the condition that the refrigerant of the system pressure PdL flows back, the high-pressure refrigerant that has flowed back is sent to the crank chamber by the capacity control valve, the crank pressure Pc (inner pressure of the crank chamber) increases excessively, and the seals and the like are damaged. Although the reliability of the apparatus may be impaired, the above-described check valve prevents an excessive increase in the crank pressure Pc by preventing the reverse flow of the refrigerant.

  However, since the check valve is also a resistance against the flow of the discharged refrigerant, it causes pressure loss and efficiency deterioration.

  Accordingly, an object of the present invention is to provide a swash plate compressor that prevents both an excessive increase in the crank pressure Pc and a pressure loss.

  The swash plate compressor according to claim 1 comprises a swash plate capable of adjusting a swing angle with respect to a rotation center axis, a piston and a cylinder, wherein the piston is driven by the swing of the swash plate, and the swash plate. A discharge chamber consisting of a crank chamber in which the head of the piston is exposed, a high pressure portion in the discharge chamber from which the gas compressed by the compression mechanism is discharged, and a low pressure portion in the discharge chamber communicating with the external system side, A swash plate type compressor having a capacity control valve for introducing a gas in the discharge chamber high-pressure section into the crank chamber via a crank chamber introduction flow path and adjusting a swing angle of the swash plate, A direction that is movably disposed between the closed position and the open position of the introduction flow path, receives a force in the direction of moving to the closed position by the low pressure part side pressure PdL, and moves to the open position by the high pressure part side pressure PdH A valve body that receives a force, and a biasing means that biases the valve body in a direction to open the crank chamber introduction flow path, and the difference between the low pressure part side pressure PdL and the high pressure part side pressure PdH (PdL-PdH) ) Exceeds the urging force of the urging means, the valve body moves to the closing position to close the crank chamber introduction flow path.

  The invention according to claim 2 is the swash plate type compressor according to claim 1, wherein the high pressure path for applying the high pressure portion side pressure PdH to the valve body has the biasing force when the low pressure portion side pressure PdL decreases. It is a gap formed by moving the valve body by the biasing force of the means.

  The invention of claim 3 is the swash plate compressor according to claim 1, wherein a high pressure path for applying the high pressure part side pressure PdH to the valve body is branched from the crank chamber introduction flow path, It is a branch flow path that guides the high-pressure part side pressure PdH from the biasing means side to the valve body.

  A fourth aspect of the present invention is the swash plate compressor according to the first aspect, wherein a high pressure path for applying the high pressure portion side pressure PdH to the valve body is provided in the crank chamber introduction flow path, and the high pressure portion side is provided. It is a step part which guides the pressure PdH from the biasing means side to the valve body.

  A fifth aspect of the invention is the swash plate compressor according to the first aspect, wherein a high pressure path for applying the high pressure portion side pressure PdH to the valve body is provided in the valve body, and the high pressure portion side pressure PdH is reduced. It is a notch part led to the valve body from the biasing means side.

  A sixth aspect of the present invention is the swash plate compressor according to the first aspect, wherein a high pressure path for applying the high pressure portion side pressure PdH to the valve body is provided in the valve body, and the high pressure portion side pressure PdH is reduced. It is a through hole leading to the valve body from the biasing means side.

  The invention of claim 7 is the swash plate compressor according to any one of claims 1 to 6, wherein the valve body has a restricted flow path having a predetermined cross-sectional area smaller than the crank chamber introduction flow path. Even when the crank chamber introduction flow path is closed, the gas is allowed to flow at a limited predetermined flow rate.

  In the swash plate compressor according to the first aspect, when the low pressure part side pressure PdL becomes larger than the high pressure part side pressure PdH, a reverse flow occurs, and when the difference (PdL−PdH) exceeds the urging force of the urging means, the valve body becomes low pressure. The crank pressure Pc is prevented from excessively rising because it is moved by the part side pressure PdL (system pressure: system side pressure) and the crank chamber introduction flow path is closed to prevent the refrigerant from flowing back into the discharge chamber. Damage to seals and lower reliability are avoided.

  In addition, as described above, since the adverse effect due to the back flow of the refrigerant can be avoided without using the check valve, the pressure loss and the efficiency deterioration due to the use of the check valve are prevented.

  The swash plate compressor according to claim 2 is configured such that when the low pressure part side pressure PdL is reduced, the high pressure part side pressure PdH is applied to the valve body through a gap formed by the urging force of the urging means moving. The backflow prevention function operates normally, and an effect equivalent to that of the first aspect is obtained.

  In the swash plate compressor according to claim 3, the backflow prevention function operates normally when the high pressure part side pressure PdH is applied to the valve body from the branch passage formed in the crank chamber introduction passage. The same effect can be obtained.

  The swash plate compressor according to claim 4 operates normally when the high pressure portion side pressure PdH is applied to the valve body from the stepped portion provided in the crank chamber introduction flow path, and is equivalent to the configuration of claim 1. The effect is obtained.

  In the swash plate compressor according to the fifth aspect, the backflow prevention function operates normally when the high pressure portion side pressure PdH is applied to the valve body from the notch provided in the valve body, and the same effect as the configuration of the first aspect is achieved. Is obtained.

  In the swash plate compressor according to the sixth aspect, the backflow prevention function operates normally when the high pressure part side pressure PdH is applied to the valve body from the through hole provided in the valve body, and the same effect as the configuration of the first aspect is achieved. can get.

  In the swash plate compressor according to the seventh aspect, even when the crank chamber introduction flow path is closed, a predetermined flow rate of gas can flow from the restriction flow path provided in the valve body. For example, if the backflow time from the system side becomes long, the crank chamber introduction flow path is closed during that time, so that no pressure is sent from the capacity control valve to the crank chamber, and the crank pressure Pc decreases and the swash plate swing angle However, in this configuration, the crank pressure Pc is prevented from being extremely reduced by the gas having a predetermined flow rate that passes through the restriction flow path.

  In addition, since the cross-sectional area of the restriction flow path is limited to be sufficiently smaller than the cross-sectional area of the crank chamber introduction flow path, the crank pressure Pc is not excessively increased.

  Further, the restriction flow path may be provided on the crank chamber introduction flow path side, and in this case, the restriction flow path may function as a high-pressure path.

<One Embodiment>
The swash plate compressor 1 will be described with reference to FIGS. 1 to 3 and FIG. 11. FIG. 1 is a longitudinal sectional view of a swash plate compressor 1, FIGS. 2 and 3 are principal sectional views of the swash plate compressor 1, and FIG. 11 is a block diagram of the system. The left and right directions are the left and right directions in FIG.

  The swash plate compressor 1 of this embodiment includes a swash plate 3 that can adjust a swing angle with respect to a rotation center axis, a piston 5 and a cylinder 7, and a compression mechanism in which the piston 5 is driven by the swing of the swash plate 3. 9, the crank chamber 13 in which the swash plate 3 is accommodated and the head 11 of the piston 5 is exposed, the discharge chamber high-pressure portion 15 to which the refrigerant (gas) compressed by the compression mechanism 9 is discharged, and the external system side Capacity control for adjusting the swing angle of the swash plate 3 by introducing the gas in the discharge chamber 19 composed of the discharge chamber low-pressure portion 17 and the high-pressure portion 15 in the discharge chamber into the crank chamber 13 through the crank chamber introduction passage 21. A valve 23 (ECV) is provided.

  Further, the swash plate compressor 1 opens the crank chamber introduction flow path 21 with the slide valve 25 (valve element) movable between the closed position and the open position of the crank chamber introduction flow path 21. A coil spring 27 (biasing means) that urges in the direction is provided, and the low pressure portion side pressure PdL (force to move to the closing position) and the high pressure portion side pressure PdH (to move to the open position) are applied to the slide valve 25. When the difference (PdL-PdH) between the low pressure part side pressure PdL and the high pressure part side pressure PdH exceeds the biasing force of the coil spring 27, the slide valve 25 moves to the closed position and the crank chamber introduction flow The path 21 is closed.

  Further, when the low-pressure part side pressure PdL is reduced, the slide valve 25 is moved by the urging force of the coil spring 27 to form a gap 29 (high-pressure path), and the high-pressure part side pressure PdH is slid through the gap 29. 25.

  Next, the structure of the swash plate compressor 1 will be described.

  The swash plate compressor 1 is used in a cooling system for a vehicle air conditioner, compresses refrigerant sucked from an evaporator, and supplies the compressed refrigerant to a condenser.

  As shown in FIG. 1, the swash plate compressor 1 includes a front housing 31, a cylinder block 33, a valve plate 35, and a rear housing 37, which are integrally fixed by through bolts 39.

  An input pulley 41 for inputting engine rotation is supported on the front housing 31 by bearings 43, and a drive shaft 45 is supported on the left and right ends of the front housing 31 and the cylinder block 33 by needle bearings 47 and 49. . An electromagnetic clutch 51 is disposed between the input pulley 41 and the drive shaft 45. The electromagnetic clutch 51 is controlled by a controller, and the electromagnetic solenoid 53 sucks the armature 55 and presses it against the input pulley 41. The input pulley 41 and the drive shaft 45 are connected, the swash plate compressor 1 is driven to rotate by the driving force of the engine, and when the operation of the vehicle auxiliary equipment is stopped, the connection is released and the swash plate compression is performed. Disconnect machine 1 from the engine.

  A plurality of cylinders 7 are formed at equal intervals in the circumferential direction on the cylinder block 33, and the piston 5 is engaged with the cylinder 7 to form a plurality of compression mechanisms 9, and the crank chamber 13 includes a front housing 31, a cylinder block 33, It is made between.

  A lug 57 is fixed to the drive shaft 45, the thrust bearing 59 receives a left thrust force applied to the drive shaft 45, and the thrust bearing 61 receives a right thrust force applied to the drive shaft 45. A sleeve 63 is slidably attached to the outer periphery of the drive shaft 45, and a journal 67 is swingably connected to the sleeve 63 via a link mechanism 65. The swash plate 3 is fixed to a journal 67, and is slidably connected to each piston 5 via hemispherical piston shoes 69, 69 on both sides of the outer edge. The sleeve 63 includes a destroke spring 71 disposed between the lug 57, a return spring 75 disposed between the retaining ring 73, a discharge pressure (Pd: PdH) and a suction pressure (Ps) of the compression mechanism 9. When the sleeve 63 moves to the cylinder block 33 side, the swing angle of the swash plate 3 (the stroke of each piston 5) is reduced, and the sleeve 63 is moved in the axial direction by the pressure difference (Pd-Ps). When moving to the lug 57 side, the swing angle increases.

  The suction chamber 77 formed in the rear housing 37 is connected to the evaporator side, the discharge chamber 15 is connected to the condenser side, and the flow rate control valve 23 moves the refrigerant from the discharge chamber 15 to the crank chamber 13 under the control of the controller. The swing angle of the swash plate 3 is adjusted by controlling the differential pressure (Pd−Ps).

  The rotational torque of the engine input to the input pulley 41 rotates the drive shaft 45 (lug 57), and this rotation is transmitted to the journal 67 (swash plate 3) via the link mechanism 65, while the swash plate 3 rotates. Each piston 5 is reciprocated at a stroke corresponding to the swing angle to drive each compression mechanism 9, and each compression mechanism 9 sucks an amount of refrigerant corresponding to this stroke, compresses it, and discharges it to the discharge chamber 19. To do.

  As shown in FIGS. 1 to 3 and FIG. 11, the slide valve 25 is a bottomed cylindrical member. The slide valve 25 includes pressure PdH from the discharge chamber high-pressure part 15 side and a biasing means for the coil spring 27. The pressure PdL from the discharge chamber low-pressure part 17 side is applied in the direction in which the crank chamber introduction flow path 21 is closed. A pressure adjusting throttle 79 is provided between the discharge chamber high-pressure portion 15 and the discharge chamber low-pressure portion 17. While the swash plate compressor 1 is being driven, the sum of the pressure PdH and the urging means of the coil spring 27 is greater than the pressure PdL. Therefore, as shown in FIG. In this state, the capacity control valve 23 sends an amount of refrigerant corresponding to the opening set by the controller from the discharge chamber 19 to the crank chamber 13, and the swash plate 3 swing angle (respective compression mechanisms) 9) is adjusted.

  When the swash plate compressor 1 is stopped or the discharge amount is minimized, the pressure PdH in the discharge chamber high-pressure portion 15 is lower than the pressure PdL in the discharge chamber low-pressure portion 17 to which the pressure from the system is applied. When the refrigerant from the side flows back to the discharge chamber high-pressure portion 15, the high-pressure refrigerant that has flowed back is sent from the capacity control valve 23 to the crank chamber 13, and the crank pressure Pc may increase excessively. However, even if the refrigerant tries to flow backward, the pressure difference (PdL-PdH) exceeds the urging force of the coil spring 27, and the slide valve 25 moves to the closed position and closes the crank chamber introduction passage 21 as shown in FIG. By doing so, the crank chamber 13 is protected from an excessive crank pressure Pc.

[Other examples of high-pressure paths]
The above-described embodiment is an example in which the gap 29 is used as a high-pressure path that guides the pressure PdH of the high-pressure portion 15 in the discharge chamber to the slide valve 25. However, there are various types of high-pressure paths. An example of another high-pressure path will be described with reference to FIG.

  In the example shown in FIG. 4, the branch passage 101 is branched from the crank chamber introduction passage 21 to form a high-pressure passage, and the pressure PdH in the discharge chamber high-pressure portion 15 is applied to the slide valve 25 via the branch passage 101. Thus, the above-described backflow prevention function is configured to operate.

  In the example shown in FIG. 5, a step portion 111 is provided in the crank chamber introduction passage 21 to form a high pressure path, and the pressure PdH in the discharge chamber high pressure portion 15 is applied to the slide valve 25 through the step portion 111. The backflow prevention function is configured to operate.

  In the example shown in FIG. 6, the notch 121 is provided in the slide valve 25 to provide a high pressure path, and the pressure PdH in the discharge chamber high pressure part 15 is applied to the slide valve 25 through the notch 121, so The prevention function is configured to operate.

  In the example shown in FIG. 7, a through hole 133 is provided in the cylindrical portion 131 of the slide valve 25 to form a high pressure path, and the pressure PdH in the discharge chamber high pressure portion 15 is applied to the slide valve 25 through the through hole 133. The backflow prevention function is configured to operate.

  In the example shown in FIG. 8, the restriction channel 143 is provided at the bottom 141 of the slide valve 25 provided with the through hole 133, and the restriction channel 145 is provided at the cylindrical part 131, and the backflow time from the system side Is longer, the crank chamber introduction passage 21 is closed during that time, so that the refrigerant pressure is not sent from the capacity control valve 23 to the crank chamber 13, the crank pressure Pc is lowered, and the swing angle of the swash plate 3 is increased. Although the discharge amount may increase, in this example, an extreme decrease in the crank pressure Pc is prevented by the refrigerant having a predetermined flow rate that passes through the restriction flow paths 143 and 145, and an increase in the discharge amount is prevented.

  FIGS. 9 and 10 show an example in which the restriction flow paths 143 and 145 are provided in the slide valve 25 provided with the notches 121, and the restriction passages 143 and 145 pass through similarly to the example of FIG. The refrigerant having a predetermined flow rate prevents the crank pressure Pc from drastically decreasing and prevents the discharge amount from increasing.

  Next, the effect of the swash plate compressor 1 will be described.

  Even if a reverse flow occurs from the system side, the slide valve 25 closes the crank chamber introduction flow path 21 due to the reverse pressure, so that the crank pressure Pc does not increase excessively, and the seal and the like are damaged and the reliability is lowered. Is avoided.

  In addition, since adverse effects due to backflow are prevented without using a check valve, pressure loss and efficiency deterioration associated with the use of the check valve can be avoided.

[Other Embodiments Included within the Scope of the Present Invention]
It should be noted that the present invention is not limited to the above-described embodiment, and various modifications can be made within the technical scope of the present invention.

  For example, the restriction flow path for flowing an appropriate amount of gas to the crank chamber introduction flow path may be provided not on the valve body but on the crank chamber introduction flow path side. In this case, the restriction flow path may be used as a high pressure path. it can.

1 is a longitudinal sectional view of a swash plate compressor 1. FIG. 2 is a cross-sectional view of a main part of the swash plate compressor 1. FIG. 2 is a cross-sectional view of a main part of the swash plate compressor 1. FIG. It is principal part sectional drawing which shows the other example of a high voltage | pressure path | route. It is principal part sectional drawing which shows the other example of a high voltage | pressure path | route. It is principal part sectional drawing which shows the other example of a high voltage | pressure path | route. It is principal part sectional drawing which shows the other example of a high voltage | pressure path | route. FIG. 6 is a cross-sectional view of a main part showing an example in which restriction channels 143 and 145 are provided in the slide valve 25. 4 is a skeleton diagram showing an example in which restriction flow paths 143 and 145 are provided in the slide valve 25. FIG. 4 is a skeleton diagram showing an example in which restriction flow paths 143 and 145 are provided in the slide valve 25. FIG. 1 is a block diagram of a system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Swash plate type compressor 3 Swash plate 5 Piston 7 Cylinder 9 Compression mechanism 13 Crank chamber 15 Discharge chamber high pressure part 17 Discharge chamber low pressure part 19 Discharge chamber 21 Crank chamber introduction flow path 23 Capacity control valve 25 Slide valve (valve body)
27 Coil spring (biasing means)
29 Clearance (high pressure path)
101 Branch flow path (high pressure path)
111 Stepped part (high pressure path)
121 Notch (high-pressure path)
133 Through-hole (high-pressure path)
143,145 Restricted flow path

Claims (7)

A swash plate (3) capable of adjusting a swing angle with respect to the rotation center axis, a compression mechanism including a piston and a cylinder, the piston being driven by swinging of the swash plate (3), and the swash plate (3) A crank chamber (13) in which the head (11) of the piston is housed and exposed, a high pressure portion (15) in the discharge chamber in which the gas compressed by the compression mechanism is discharged, and a discharge chamber communicating with the external system side The gas in the discharge chamber (19) composed of the low pressure portion (17) and the high pressure portion (15) in the front discharge chamber is introduced into the crank chamber (13) through the crank chamber introduction flow path (21), and the swash plate ( A swash plate compressor (1) provided with a capacity control valve for adjusting the swing angle of 3),
The crank chamber introduction flow path (21) is movably disposed between a closed position and an open position, receives a force in a direction of moving to the closed position by the low pressure part side pressure PdL, and receives the force by the high pressure part side pressure PdH. A valve body (25) that receives a force in a direction to move to the open position;
An urging means (27) for urging the valve body (25) in a direction to open the crank chamber introduction flow path (21);
When the difference (PdL-PdH) between the low pressure portion side pressure PdL and the high pressure portion side pressure PdH exceeds the urging force of the urging means (27), the valve body (25) moves to the closed position and the crank chamber A swash plate compressor (1) characterized in that the introduction channel (21) is closed. A swash plate compressor (1) according to claim 1,
The high pressure path for applying the high pressure part side pressure PdH to the valve body (25) is formed by the valve body (25) being moved by the urging force of the urging means (27) when the low pressure part side pressure PdL is lowered. A swash plate compressor (1) characterized in that it is a gap (29). A swash plate compressor (1) according to claim 1,
A high pressure path for applying the high pressure portion side pressure PdH to the valve body (25) is formed by branching from the crank chamber introduction flow path (21), and the high pressure portion side pressure PdH is supplied from the biasing means (27) side to the valve. A swash plate compressor (1), characterized in that it is a branch channel (101) leading to the body (25). A swash plate compressor (1) according to claim 1,
A high pressure path for applying the high pressure part side pressure PdH to the valve body (25) is provided in the crank chamber introduction flow path (21), and the high pressure part side pressure PdH is supplied from the biasing means (27) side to the valve body (25 A swash plate compressor (1), characterized in that it is a step (111) leading to A swash plate compressor (1) according to claim 1,
A high pressure path for applying the high pressure portion side pressure PdH to the valve body (25) is provided in the valve body (25), and the high pressure portion side pressure PdH is guided from the biasing means (27) side to the valve body (25). A swash plate compressor (1) characterized by being a notch (121). A swash plate compressor (1) according to claim 1,
A high pressure path for applying the high pressure portion side pressure PdH to the valve body (25) is provided in the valve body (25), and the high pressure portion side pressure PdH is guided from the biasing means (27) side to the valve body (25). A swash plate compressor (1) characterized by being a through hole (131). A swash plate compressor (1) according to any one of claims 1 to 6,
The valve body (25) is provided with restriction passages (143, 145) having a predetermined cross-sectional area smaller than the crank chamber introduction passage (21), and the crank chamber introduction passage (21) is closed, A swash plate type compressor (1) characterized by flowing gas at a limited predetermined flow rate.

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