JPS6172885A - Shock absorber in swash plate type variable displacement compressor - Google Patents

Abstract

PURPOSE:To aim at preventing a driving feeling from worsening, by installing a capacity selector mechanism for opening of closing a first bypass passage and a control valve, gradually closing all passages by means of dynamic pressure of reflux gas inside a second bypass passage with closure of this passage both inside a discharge chamber. CONSTITUTION:Compressed high temperature discharge gas is fed, with pressure, to a back pressure chamber 57 via a high pressure pipe 60, while a spool 47 is moved to a regular closing position together with a discharge valve 44 and a valve guard 46, closing a first bypass passage 56. Therefore, the whole quantity of gas discharged to the discharge chamber 22 passes through a second passage 65 alone and is made to flow back to a swash plate chamber 8 whereby a control valve 67 tries to be moved in a direction to close the passage 65 by dint of dynamic pressure of reflux gas, but since the intake of pressure compensating for negative pressure in a back pressure chamber 69 is throttled by a pressure intake hole 70, its motion is regulated so as to come sluggish, and a gas quantity is gradually increased till the control valve 67 comes to 100% operation having closed the passage 65 completely so that with this increase, engine load also slowly goes up, therefore a shock is effectively relievable.

Description

Detailed Description of the Invention Object of the Invention (Industrial Application Field) The present invention relates to a swash plate type variable capacity compressor suitable for vehicle air conditioning, and more specifically, to a swash plate type variable capacity compressor suitable for vehicle air conditioning, and more specifically, to reduce the deterioration of driving feeling when cooling output is increased. This invention relates to a shock mitigation device that prevents shocks.

(Prior art) In general, in vehicle air conditioners, when the compressor is operated intermittently for the purpose of capacity control, etc., a sudden increase in engine load at startup causes symptoms similar to engine braking, so-called This results in deterioration of the driving feeling due to the startup shock.

In order to eliminate the above disadvantages, a variable capacity type (unexamined patent application) is designed to reduce the engine load by disabling half of the compressor at 50% operation at start-up, and shifting to 100% operation at the appropriate timing. No. 57-738775) has also been proposed, but even though it was halved at the time of startup, the
The load equivalent to % operation is suddenly added, and the increase in load is also instantaneous during the transition from 50% operation to 100% operation, so it is impossible to completely alleviate the shock mentioned above, that is, to prevent deterioration of driving feeling. It's hard to predict. Among the operating shocks that cause this deterioration of feeling, when starting the compressor when the electromagnetic clutch is connected,
This shock occurs after the driver performs an action based on the driver's intention, such as turning on the air conditioner switch, and is expected.The shock is not that different, but it is caused by a detection signal from a temperature sensor, etc. Based on 50% operation to 1
When shifting to 00% operation, the output is increased regardless of the driver's intention, so the shock in this case, that is, the deterioration of the driving feeling, is of particular concern.

(Problems to be Solved by the Invention) In order to eliminate the above-mentioned drawbacks, the present invention aims to solve the problem by providing a control function 11 that can suppress a sudden increase in engine load when the output of the compressor is increased. This is a problem that should be addressed.

Structure of the Invention (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention separates a high pressure chamber, such as a discharge chamber, and a low pressure chamber, such as a suction chamber, on the rear side by providing two chambers that are separated and penetrated through the rear side plate. A back pressure chamber communicates with the first and second bypass passages including communication holes, and is located at a position facing the first bypass passage opening of the high pressure chamber, and receives a compressor start/stop signal or a cooling load detection signal. A spool that selectively communicates with the low pressure chamber and the front high pressure section to open and close the first bypass passage and disable the compression function on the rear side, and the back pressure chamber of the pool is connected to the low pressure chamber. A capacity switching mechanism is provided at a position facing the second bypass passage opening of the high pressure chamber, and a spring that biases the spool in the direction of opening the spool and keeps it floating when the spool is in communication with the spool. a control valve that operates in a direction to close the opening of the second bypass passage and adjusts the degree of opening thereof by the dynamic pressure of the recirculated gas contained in the accommodation recess and flowing through the second bypass passage to the low pressure chamber; , a pressure guide hole having a throttling effect that communicates a back pressure chamber formed at the bottom of the accommodation recess of the control valve with the high pressure chamber, and 1, 1 in which the pressures acting in the forward and backward directions of the control valve are balanced. The method is to provide a shock-reducing mechanism consisting of a spring that biases the control valve in the direction of opening and holds it floating.

(Function) The compressor is in a 50% operating state, that is, complete compression work is performed on the front side, and the discharge gas is released on the rear side. In a state where the compression work is substantially disabled by flowing back from the second bypass passage to a low pressure chamber such as a swash plate chamber, the capacity switching mechanism is switched to a 100% operating state by a detection signal from a temperature sensor, etc., and the first bypass When the passage is closed,
All of the discharged gas on the rear side is recirculated from the second bypass passage, and the dynamic pressure of the recirculated gas acting on the control valve is increased. Therefore, the control valve tries to operate in the direction of closing the second bypass passage against the biasing force of the spring, but the introduction of pressure to compensate for the negative pressure in the back pressure chamber is restricted by the pressure guiding hole. , the movement is adjusted so that it is slow.

As this control valve approaches the opening of the bypass passage,
Since the flow rate of the reflux gas is gradually restricted, the pressure in the high pressure chamber increases, and the number of gas ports sent to the cooling circuit gradually increases until the bypass passage is completely closed and 100% operating. Therefore, the engine load increases gradually as the actual compression work increases;
The shock is effectively alleviated.

In addition, the capacity switching mechanism is 50% in the 100% operating state.
When switched to operation, the first bypass passage is opened, so that the gas pressures acting on both front ends of the control valve are balanced in a low pressure state, and the control valve returns to the open position by the biasing force of the spring.

(Example) Hereinafter, an example embodying the present invention will be described based on FIGS. 1 to 4. This compressor has 5 cylinders on each side, or 10
Both ends of the cylinder block 1.2, which are opposed in the figure, are closed by both front and rear housings 5, 6, which are joined via valve plates 3, 4, which are arranged in appropriate numbers. It is assembled with real bolts 7.

A swash plate chamber 8 is formed at the joint portion of the cylinder block 1.2, and is fixed thereto at an angle with respect to a drive shaft 9 passing through shaft holes ia and 2a provided through the center of the cylinder block 1.2. A swash plate 10 is housed therein. The boss portions 11.12 of the cylinder blocks 1 and 2 through which the drive shaft 9 passes are provided with radial bearings 13.14 that support the drive shaft 9.
is press-fitted therein, and a thrust bearing 15.16 is interposed between the boss portion 11.12 and the swash plate 10.

In the cylinder block 1.2, five-phase cylinder bores 17 are arranged parallel to the drive shaft 9 and radially around the drive shaft 9, and the screws 1 to 18 inserted into the cylinder bore 17 are The piston 18 is moored to the swash plate 10 via a bearing device consisting of a ball 19 and a shoe 20, and the piston 18 can reciprocate within the cylinder bore 17 by the rotational force of the swash plate 10. Front and rear housings 5.6
A discharge chamber 21.22 is formed on the center side, and a substantially annular suction chamber 23.24 is formed on the outer circumferential side so as to surround the discharge chamber 21.22.In particular, the discharge chamber 21 on the front side is The discharge chamber 22 on the rear side is formed in a cylindrical shape. The suction chambers 23 and 24 are connected to the swash plate chamber 8 by suction passages 25 and 26 which also serve as through holes for the bolts 7.
The swash plate chamber 8 is in communication with a suction flange 27 mounted near the mating surface of the cylinder block 1.2.

Further, a discharge passage 28.29 is bored at one location between the bores in the cylinder blocks 1, 2 from the contact surface with the valve plates 3, 4 to the mating surface.
29 has one end communicating with a discharge flange 30 mounted near the joint of the cylinder blocks 1 and 2 through communication holes 31, 32 and 35, respectively, and a narrow end communicating with the valve plate 3 and 4.
The discharge chamber 21 through the communication hole 33.3/I provided through the
It is connected to 22. However, the communication portion of the discharge chambers 21.22 with the discharge passages 28.29 is appropriately bulged toward the outer circumferential side. Further, a check valve 36 is provided in the rear communication hole 32 to prevent gas from flowing backward from the discharge passage 28 to the discharge passage 29 via the discharge flange 30.

The valve plates 3, 4 are provided with suction ports 37, 38 and discharge ports 39.
40 are provided through the cylinder bore 17, through which the cylinder bore 17 communicates with the suction chamber 23.24 and the discharge chamber 21.22, respectively, and these suction ports 37.38 and discharge ports 39, 4
．． 0 each have a suction valve 41. /12 and discharge valve 43.
44 are arranged. Furthermore, the amount of deformation of the discharge valves 43, 44 is regulated by an interposition 45° 46,
On the front side, it is clamped and fixed between the valve plate 3 and the front housing 5, but on the rear side, with an insert 46, it has two positions: a normal closed position and a listening position that opens the discharge port 40. It is possible to switch to

That is, the rear insert 46 has the same shape as the discharge valve 44 as shown in FIG.
1, and a lead portion 46b that extends to face the discharge valve 44 and the interposed insert 46, which are overlapped as shown in FIG. The cylindrical spool 47 that is in contact with the spool 47 is integrated with a bolt 48, and the spool 47 is slidably fitted in the circular recess 49 defined by the partition wall 6a in the center of the rear housing 6 in the axial direction. has been done. The three members integrated by the bolts 48 are prevented from rotating by a positioning pin 50 implanted in the partition wall 6a of the rear housing 6.

At the rear end of the shaft hole 2a formed in the center of the rear cylinder block 2, there is a circular hole that communicates with the center of the discharge chamber 22 through a communication hole 52 penetrated through the center of the valve plate 4. A space 51 is formed.

A disk-shaped spring receiver 53 is fitted into the circular space 51, and the discharge valve 7I/
A spring 54 is housed therein which constantly biases the l to float to the position. In addition, a small hole 53a is provided through the spring receiver 53 to communicate the shaft hole 2a and the circular space 51, and the rough A7 side side 1, 1 dowel block 2 has a swash plate chamber 8 and the circular space 51. A communication path 55 for communication is formed. When the discharge valve 44 is held in the open position, the discharge chamber 22 communicates with the swash plate chamber 8 through a first bypass passage 56 consisting of a circular space 51, a communication hole 52, and a communication passage 55. However, when the discharge valve 44 is displaced to the normal closed position, the communication is cut off.

[1] The core of the housing 6 described above is equipped with a lifting and cutting mechanism that switches the compression capacity using static pressure, and this mechanism is
It consists of a spool 47, a pressure guiding hole 58 that guides pressure to the spool back pressure chamber 57, and the spring 54, and this pressure guiding hole 58
is connected to the discharge flange 30 or the fluorocarbon 1 to the side discharge chamber 21 through a high pressure pipe 60 including a first solenoid valve 59, and is also connected to the suction flange 27 through a low pressure pipe 62 including a second solenoid valve 61. When the pressure inside the rear discharge chamber 22 is low, the check valve 36 closes the communication hole 32, and when the pressure inside the rear discharge chamber 22 is high, the check valve 36 opens the communication hole 32.

Further, a shock mitigation mechanism Ia, which is an important part of the present invention, is provided in the V side outlet chamber 22 to alleviate the shock when switching the capacity from 50% operation to 100% operation. To explain this shock mitigation mechanism, the rear valve plate 4
A communication hole 63 and a communication passage 64 branched from the first bus pass passage 56 are respectively provided through the cylinder block 2, and by communicating with each other, the discharge chamber 22 and the swash plate chamber 8 are connected with ample space and a large passage area. A second bypass passage 65 communicating therewith is formed.

In the discharge chamber 22 of the rear housing 6, a cylindrical accommodation recess 66 formed corresponding to the communication hole 63 is provided with the communication hole 63 (the discharge chamber 2 of the second bypass passage 65).
A control valve 67 that can open and close the second side opening) using dynamic pressure is fitted. A spring 68 is interposed between the control valve 67 and the valve plate 4, so that the control valve 67 is always kept floating in the open position. The control valve 67 has a discharge chamber 2
2 and a back pressure chamber 69 formed on the back side of the control valve 67. A pressure guiding hole 70 is provided through the control valve 67 to perform a throttling action to communicate between the discharge chamber 22 and the back pressure chamber 69 formed on the back side of the control valve 67. I try to avoid it. Note that the guiding pressure 7L 70 may be provided on the rear housing 6 side.

Next, the operation of the swash plate type variable capacity compressor constructed as described above will be explained.

Stop I: At IIY, as shown in FIG. 1, the spool 47 of the capacity switching mechanism is held floating together with the discharge valve/14 in a position where the first bypass passage 56 is opened by the spring 54, and the check valve 36 is in communication. The hole 32 is closed, the first solenoid valve 59 is turned on, and the second solenoid valve 61 is closed. Further, the control valve 67 of the shock mitigation mechanism is held floating by a spring 68 at a position where it opens the second bypass passage 65. When the compressor is started in such a state, compression is effectively performed at 50% capacity on the front side, but since the first and second bypass passages 56, 65 are open on the rear side, the discharge is reduced. All the gas discharged into the chamber 22 is recirculated to the swash plate chamber 8, and the compression work on the rear side is nullified.
It is started with % Yongyu. At this time, the amount of gas recirculated from the second bypass passage 65 is approximately half of the rear side discharge gas, so the dynamic pressure of the recirculated gas resists the biasing force of the spring 68 and moves the control valve 67 in the closing direction. Without being moved, the control valve 67 remains in the open position.

After that, the gas compressed on the front side is discharged from 7 lunges 3
0, this high-pressure discharged gas is fed to the back pressure chamber 57 via the high pressure pipe 60, and the internal pressure (static pressure) of the back pressure chamber 57 increases.
Along with the upper back of the spool 47, the discharge valve 44 and the valve holder 4
6 to the normal closed position, and the first
Bypass passage 56 is closed. Therefore, the gas discharged from the discharge lower IO to the discharge chamber 22 is vigorously recirculated to the swash plate chamber 8 through only the second bypass passage 65, and as a result, the control valve 67 is activated by the dynamic pressure of the recirculated gas. The second bypass passage 65 attempts to close against the biasing force of the second bypass passage 68, but the introduction of pressure to compensate for the f1 pressure in the back pressure chamber 69 is restricted by the pressure guiding hole 70. So,
The movement is adjusted to be slow. This control valve 67
As the gas approaches the open end of the second bypass passage 65, the flow of the recirculated gas is restricted and the pressure in the discharge chamber 22 also increases. Then, the amount of gas sent to the cooling circuit gradually increases until the control valve 67 reaches 100% operation with the second bypass passage 65 completely closed, and the engine load gradually increases accordingly, so the shock is effective. will be alleviated.

On the other hand, in the 100% operating state, when the cabin temperature drops below the set temperature and becomes overcooled, the cooling load detection signal closes the first solenoid valve 59 and opens the second solenoid valve 61, so that the spool 47 The back pressure chamber 57 becomes low pressure, and the spool 47, together with the discharge valve 44 and the valve retainer 46, releases the spring 5.
4, it is held floating in the open position and switched to 50% operation.

At this time, the discharge chamber 22 enters the first bypass passage 56 and is in a low pressure state balanced with the pressure in the swash plate chamber 8, so the pressure inside the back pressure chamber 69 of the control valve 67, which is in a high pressure state, is reduced to the pressure guiding hole 70.
As a result, the pressure on both the front and rear sides of the control valve 67 is balanced, and the control valve 67 is floated and held in the open position by the spring 68, thereby reducing the shock during the next transition from 50% to 100% operation. Be prepared for mitigation. Note that when the compressor is stopped in the 50% operating state, the stop signal causes the solenoid valve 59 to open and the solenoid valve 61 to close, restoring the original state.

Note that the present invention can also be embodied in the following embodiments.

In the above embodiment, the rear discharge valve 44 is made switchable between the normal closed position and the open position, with 50% operation and 1
00% operation switching was performed, but the discharge valve 4
4 is fixed to the valve plate 4 together with the valve retainer 46, and the spool 47
The communication IL 52 is opened and closed by a chisel, and the back pressure chamber 57 and the suction flange 27 are communicated by a low pressure pipe including a solenoid valve, and the spool 47 is opened and closed by the opening and closing operation of the solenoid valve. The operation shall be switched.

The tip of the control valve 67 should be provided with folds or grooves to make it easier to receive the dynamic pressure of the gas.

Effects of the Invention As detailed above, the present invention provides a capacity switching mechanism including a spool disposed in the rear discharge chamber of a compressor that opens and closes a first bypass passage by static pressure drive, and a capacity switching mechanism for opening and closing the first bypass passage. It is especially automatic because it is equipped with a shock mitigation mechanism including a control valve that slowly closes the second bypass passage by moving slowly due to the dynamic pressure of the fast-flowing gas that concentrates in the second bypass passage when the second bypass passage is closed. 1 from 50% operation controlled
The transition to 00% operation can be performed gradually, and deterioration of driving feeling due to sudden changes in engine load can be effectively prevented.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the present invention, FIGS. 1 and 2 are longitudinal cross-sectional views of the central part, and FIG. 3 is an A in FIG. 1.
-A line sectional view, and FIG. 4 is a longitudinal sectional view showing the gas flow part of the discharge port. Jill cylinder block 1.2, valve plates 3, 4, front housing 5, rear housing 6, swash plate chamber 8, cylinder bore 1
7, discharge chamber 21.22, suction chamber 23.24, discharge passage 2
8.29, check valve 36, discharge valve 43.44, spool 4
7, circular recess 49, spring 54.68, 1st. Second bypass passage 56.65, back pressure chamber 57.69, first solenoid valve 5
9, second solenoid valve 61, high pressure pipe 60, low pressure pipe 62, accommodation recess 66, control valve 67°

Claims (1)

[Claims] 1. A high-pressure chamber such as a discharge chamber on the rear side and a low-pressure chamber such as a suction chamber are communicated through first and second bypass passages including two communicating holes separated from each other through the rear side plate, and the first bypass of the high-pressure chamber A back pressure chamber, located at a position facing the passage opening, selectively communicates with the low pressure chamber and the front side high pressure section in response to a compressor start/stop signal or a cooling load detection signal, and opens and closes the first bypass passage. It is composed of a spool that enables the compression function on the rear side to be disabled, and a spring that biases the spool in the direction of opening and keeps it floating when the back pressure chamber of the pool communicates with the low pressure chamber. A capacity switching mechanism is disposed in the high-pressure chamber at a position opposite to the second bypass passage opening, and a storage recess is provided in the high-pressure chamber at a position facing the second bypass passage opening, and a reflux gas contained in the recess and flowing to the low-pressure chamber via the second bypass passage second due to the dynamic pressure of
A control valve that operates to close the opening of the bypass passage and adjusts its opening, and a guiding pressure having a throttling effect that connects the high pressure chamber to a back pressure chamber formed at the bottom of a housing recess for the control valve. A swash plate type variable variable valve equipped with a shock mitigation mechanism consisting of a hole and a spring that biases the control valve in the direction of opening and holds it floating when the pressures acting in the forward and backward directions of the control valve are balanced. Shock mitigation device in capacity compressor.