JPH01101219A - Compressor structure for vehicle air conditioner - Google Patents

Abstract

PURPOSE:To improve a cooling down performance of a refrigerant compressor which conducts a variable capacity control by means of the pressure of an inclined plate back surface by arranging so as to change the set pressure of a control valve according to the discharge pressure of the compressor. CONSTITUTION:When head load increases, the discharge pressure Pd of a com pressor also increases. This discharge pressure Pd enters a hollow bellows 45 through an introduction pipe 47, and extends the hollow bellows 45. According ly, a distance between a spring seat 36 and a sub end cap 43 is lessened as a downward moving plate 44 moves downward. Accordingly, a rod 39, a valve pin 24 also move downward and a ball 23 nears a seat surface 26 and a set value S0 becomes small. Conversely, when the discharge pressure Pd lowers, the set value S0 becomes large. As a result, the set value of a control valve will be changed according to the heat load, and a cooling down performance can be improved while the freezing of an evaporator is being prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to the structure of a compressor used to pressurize refrigerant in a vehicle air conditioner, and which performs variable capacity control based on the pressure behind the swash plate.

BACKGROUND ART Conventionally, in a vehicle air conditioner as shown in Fig. 10, a so-called swash plate type compressor is used to introduce suction side pressure to the back of the swash plate, thereby changing the inclination of the swash plate to discharge air. A structure for varying the capacity tt has been proposed (Japanese Patent Application Laid-open No. 58
(Refer to Publication No. 158382) In other words, in the figure, 1 is a wobble-type compressor 37, and a rotating shaft 5 that is rotated by a belt 3 via a pulley 4 is provided in the casing 2 of the compressor 1. A rotary drive plate 6, which rotates integrally with the rotary shaft 5, is pivotably supported in an oblique manner, and a non-rotary wobble 8 is attached to a journal 7 of the rotary drive plate 6. Note that 9 indicates a bearing.

(-t, t) The non-rotary wobble 8 is connected to a piston 11 in the four cylinder cylinders 10 through a rod 12, and the piston reciprocates when the rotary drive plate 6 rotates. , the refrigerant is delivered from the suction side chamber 13& to the discharge side chamber 13b, and the next refrigerant is pumped to the condenser 14, orifice tube 15°, evaporator 16, and accumulator 17.

Here, by introducing the suction side pressure to the back side of the non-rotary wobble 8, as the one rotation increases, the inclination automatically decreases and the compressor tilts in a direction perpendicular to the rotation axis 5. This is to reduce the capacity of 1.

Further, a communication passage 18 is provided between the suction side chamber 13m and the discharge side chamber 13b, and in this communication passage 18, the suction pressure P@ of the suction @ 'M 13 m and the discharge side chamber 13 are connected.
A control pulp 19 is provided which is activated when the discharge pressure Pd of b reaches a predetermined set value to communicate the suction side chamber 13a and the discharge side chamber 13b, and the refrigerant also functions as a lubricant. When the amount of refrigerant returning to the suction side N13& decreases, refrigerant is supplied from the communication passage 18 to prevent seizure of rotating and sliding parts.

Problems to be Solved by the Invention However, in such a conventional structure, the set value at which the control pulp 19 operates is determined in advance from the relationship between the suction pressure P and the discharge pressure Pd, and the set value is adjusted to the set value. The control pulp 19t is configured to operate uniquely based on the control pulp 19t.

On the other hand, as shown in Figures 8g and 9, the cooling characteristics of the evaporator 16 are determined by the relationship between the suction pressure P3 and the discharge pressure Pd, and when both pressures Ps r Pd are below a certain value, an evaporator frozen region E occurs. Therefore, assuming a case where the heat load is large, if the control pulp 19 is operated with the set value S1 shown in the figure, excellent cool-down performance can be obtained. It becomes easier. Conversely, assuming the case where the heat load is small, the above set value S1
If the control valve 2 is operated with a set value S where the suction pressure P is larger, freezing of the evaporator 16 can be prevented, but there are disadvantages such as a decrease in cool-down performance.

The present invention was developed in view of these conventional problems, and it is possible to obtain excellent cool-down performance while avoiding freezing of the evaporator by controlling and changing the 5 operation setting values of the control pulp. The present invention provides a compressor structure for a vehicle air conditioner.

Elaborate Means for Solving the Problems In order to solve the above problems, the present invention provides an air system ff1o that performs variable displacement control using the pressure behind the swash plate.
In a structure in which a control pulp for controlling the pressure is provided inside the compressor, a set value control means is provided for changing and controlling the set value in accordance with the discharge pressure of the compressor.

Effect In the above configuration, since the discharge pressure of the compressor changes depending on the heat load of the air conditioner, by controlling and changing the set value of the control pulp according to the discharge pressure, the set value is substantially changed to the above air conditioner. The control will be changed depending on the heat load of the device. By operating the control pulp based on the set value that is changed and controlled in accordance with the heat load, the pressure on the back of the swash plate is controlled in relation to the heat load, and the capacity of the compressor is controlled by the heat load. It is controlled appropriately according to the load.

Example An embodiment of the present invention will be described below with reference to the drawings.

That is, as already explained with reference to FIG. A rotary drive plate 6 that rotates integrally with the rotary drive plate 6 is pivotally supported in an oblique manner, and a journal 7 of the rotary drive plate 6 has a
A non-rotary wobble 8, which is a swash plate, is installed.

The non-rotary wobble 8 is connected to a piston 11 in the cylinder block 10 via a rod 12e, and when the rotary drive plate 6 rotates, the piston 11? By reciprocating, the refrigerant is sent from the suction side chamber 1ia to the discharge side chamber 13b, and the condenser 14, orifice tube 15° evaporator 1
6. The granular refrigerant is force-fed to the accumulator 17, which constitutes an air conditioning system.

By introducing the suction side pressure to the back side of the non-rotary wobble 8, as its rotation increases, the inclination automatically decreases and tilts in the direction perpendicular to the rotation axis 5, increasing the capacity of the compressor 1. It is supposed to decrease.

Further, a communication passage 18 is provided between the suction side chamber 1!13a and the discharge side chamber 13b, and within this communication passage 18,
As shown in FIG. 1, there is a control valve 19 which is activated to communicate the suction side chamber 13a and the discharge side chamber 13b when the suction pressure PI of the suction side chamber 13& and the discharge pressure Pd of the discharge side chamber 13b reach predetermined set values. It is disposed within the valve block 20. In the control valve 19, inside the valve body n having an opening 9s21 on the tip side,
A valve bin 24 with a ball 23 integrally attached to its tip is installed inside, and the ball 23 is pressed against the seat surface 26 by a spring 25, and is connected to a high pressure chamber 28 communicating with a discharge side chamber 13blC@1 boat 27 and a pulp body η. It is designed to block the low pressure device communicating with the suction side chamber 13a formed inside.

In addition, 30i1E2 port, 31[@3 boat, 321!
The fourth port, 33, indicates the fifth boat.

In addition, there is a bellows 3 inside the base side of the pulp body 220.
4 and nine end caps 35T-fitted.

A spring seat 36 and an end member 37 are attached to both sides of the bellows 34, which are interposed between the spring seat 36 and the end member M, and a nine spring 38 biases the bellows 34t in the direction of extension. be.

A rod 39 is provided passing through the end member 31 from the concave portion of the spring seat 36, and the tip gs of this rod 39 is in contact with a concave portion provided at the base of the valve pin 24.

In addition, between the end cap device and the bellows 34 (7), there is a control room connected to the suction side chamber 13 & through the end cap device and the WC6 boat chrysanthemum formed in the pulp block, and the seventh port 41. The control chamber 42 also communicates with the fifth port 33.

Ha, on the proximal side of the end cap device above! A sub-end cap 43 is attached, and inside the sub-end cap 43 is a movable plate 4 that comes into contact with the lower surface of the spring seat 36.
4 pieces are included. A middle chamber bellows 45 is interposed between the movable plate shrine and the end camp, and the hollow bellows 45 has a first return spring 46t inside.
- It is bullet-loaded and communicates with the introduction pipe 47 that guides the discharge pressure Pd.

A second return spring 4B that biases the movable plate 44 upward is interposed between the movable plate 44 and the sub-end cap 43, and the second return spring 48.
The hollow bellows 45, i! 1 return spring 46, movable plate 44, etc. constitute set value control means.

In this embodiment having the above configuration, when the compressor 1 is driven, the refrigerant is transferred from the discharge side chamber 13b to the condenser 14. Orifice tube 15. Evaporator 16. Returning to the suction side chamber 13a via the accumulator 17', the desired air conditioning state is maintained by opening and closing each door such as an air mix door (not shown).

During this time, if the differential pressure between the suction side chamber 13a and the discharge side chamber 141L gradually increases and becomes larger than the set value So determined by the springs 25, 38, etc., the bellows expands, causing the rod 39.

The valve bottle 24 is pressed and the ball 23 hits the seat surface 26.
Away from the 1st to 7th boats 27, 30, 31,
32, 33° 40, 41 communicate with the suction side chamber 13a
As a result, the pressure in the suction side xtaa or the discharge side chamber 13b is guided to the back side of the non-rotary wobble 8, and the non-rotary wobble 8 is moved in a direction perpendicular to the rotating shaft 5. The capacity of the compressor 1 decreases.

Here, the relationship between the discharge pressure Pd and the heat load with respect to the amount of air conditioning equipment exhibits a characteristic as shown in FIG. 2, and the two are in a proportional relationship. Therefore, when the thermal load increases, the discharge pressure Pd also increases, and as the discharge pressure Pd is guided into the hollow bellows 45 through the introduction pipe 47, the hollow bellows 45 expands.

As a result, the movable plate 44 moves downward against the force of the Wc2U turn spring, thereby causing the spring seat 36 to move downward.
also moves downward, and the fimi spring seat 3
The distance htx between the sub-end cap 43 and the sub-end cap 43 decreases. Therefore, as the spring seat 36 moves downward, the rod 39. The valve pin 24 also moves downward, bringing the ball 23 closer to the seat surface 26, so that the spring 25
and 38.

is a small value.

Conversely, when the discharge pressure Pd decreases, the hollow bellows 35 @
The spring seat 3 is contracted together with the first return spring 46 by the urging force of the second return spring.
While moving upward by 6, the distance h [increases.

Therefore, as the spring seat 36 moves upward,
Rod 39. The valve bin 24 also moves upward, and the ball 23
is connected from the seat surface 26, and as a result, the set value So determined by the spring 25 and the rear becomes large. That is, as shown in FIG. 3, the set value So of the control pulp 19 is inversely proportional to the discharge pressure P4. °Here, the discharge pressure Pd is proportional to the heat load of the air conditioner as described above and shown in Figure WJ2, so the set value is 5.
Inversely proportional control in accordance with the relationship between et and discharge pressure Pd is substantially the same as inversely proportional control in relation to the thermal load. Then, by operating the control pulp 19, the pressure introduced to the back side of the non-rotary wobble 8 is also substantially changed and controlled in relation to the heat load of the air conditioner. For this reason, as shown by the chain line in FIG. 9, the set value So at which the control pulp 19 operates in this embodiment is the evaporator freezing region E? It becomes possible to change the control to a range where cool-down performance is improved while avoiding freezing, and it is possible to obtain excellent cool-down performance while preventing freezing of the evaporator 16.

Figure @4 shows a second embodiment of the present invention, in which a movable plate 49 fixed to a spring seat 36 is connected to a plunger 51 of an electromagnetic actuator group, which is a set value control means, and also has a plunger 51 connected to the electromagnetic actuator. A return spring 52f that presses the movable plate 49 is located in the local part of the group.
: It is arranged. The electromagnetic actuator 50 is connected to the output port of the control amplifier through a relay terminal t-+ as shown in FIG. A discharge pressure sensor 55 is connected which outputs a signal when .

In the second embodiment having the above configuration, when the discharge pressure Pd is low, the discharge pressure sensor 55 does not output a signal, so that the electromagnetic actuator 50 is maintained in a demagnetized state. Therefore, the movable plate 49Fi is held at the position (a) shown in FIG. 4 by the biasing force of the return spring, and the setting value Sod at which the control pulp 19 operates is set to a high value as shown by the chain line in FIG. maintained. When the discharge pressure Pd increases, the discharge pressure sensor 55 senses this and inputs a signal to the control amplifier group, and the control amplifier 54 supplies current to the relay group. Therefore, the relay group is turned on, an excitation current is applied to the electromagnetic actuator, and the plunger moves into the electromagnetic actuator 50. Therefore, the movable plate 49 is displaced to the (b) position below the a1 position,
The spring seat 36 fixed to the movable plate 49 is similarly displaced downward. For this reason, the above setting value S.

is set to a low value as shown in FIG. 6, and thus the set value Sat can be controlled in two stages.

Figures 7 and 8 show a third embodiment of the present invention, in which a shaft 56 is fixed to the spring seat 36.
The shaft group is provided with a rack 5'7. On the other hand, a pin 59 is attached to the rotating shaft of the motor serving as set value control means, and the pin 59 meshes with the rack. The motor 58 is configured on the output port of the control amplifier ω, and a discharge pressure sensor a is provided at the input port of the control amplifier ω to detect the discharge pressure Pd.
It is fully connected to the acceleration sensor Q that detects the acceleration of the vehicle.

In the third embodiment having the above configuration, when the discharge pressure Pd changes, the discharge pressure sensor 61 inputs a corresponding signal to the control amplifier Q, and the control amplifier 61
C. The motor 58 is controlled in steps according to the above signal. Therefore, as the motor rotates, it is driven by the rack Fi, and thereby the spring seat 36 is driven by the distance hH between the center axes.
Change. Then, as shown in FIG. 9, the set value So is changed and controlled in accordance with the discharge pressure P, 1, similar to the characteristics of the first embodiment, and the same effects as the first embodiment are achieved.

Further, in order to rapidly accelerate, the accelerator pedal is suddenly depressed, and the motor 58 is rotated so that the control amplifier 60 and the shaft group move upward. This allows shaft 5
6. Spring seat 36, rod 39, pulp pin 24'f: When pressed, the ball 23 separates from the seat surface 26, and the non-rotary wobble 8 rises in a direction perpendicular to the rotating shaft 5. Therefore, the capacity fl of the compressor 1 is quickly reduced, and the load on the engine can be reduced at the same time as the accelerator pedal is depressed in the early stages of acceleration, making it possible to prioritize the acceleration performance of the vehicle.

DETAILED DESCRIPTION OF THE INVENTION As described above, the present invention includes a control that operates based on a predetermined set value and controls the pressure within the compressor of an air conditioner that performs variable capacity control using the pressure behind the swash plate. Pulp was provided, and at t[i, the set value was changed and controlled according to the discharge pressure of the compressor. Therefore, since the discharge pressure of the compressor changes depending on the heat load of the air conditioner, by changing and controlling the set value of the control pulp according to the discharge pressure, the heat load of the air conditioner can be substantially adjusted to the set value. Changes will be controlled accordingly. By operating the control pulp based on the set value that is changed and controlled in accordance with the heat load, the pressure at the back of the slope is controlled in relation to the heat load, thereby avoiding freezing of the evaporator. This makes it possible to obtain excellent cooldown performance at the same time.

[Brief explanation of the drawing]

Figure wc1 is an enlarged sectional view of part A in Figure 1O showing the first embodiment of the present invention, Figure 2 is a characteristic diagram of air conditioner heat load vs. discharge pressure Pd, and Figure 3 is a diagram showing control pulp set value So vs. discharge pressure P.
The second embodiment of the present invention is shown in the d characteristic diagram and the wc4 diagram @10
FIG. 5 is a block diagram of the same embodiment, FIG. 6 is a set value So change characteristic diagram of the same embodiment, and FIG. 7 is a diagram showing the third embodiment of the present invention. 8 is a block diagram of the same embodiment, and FIG. 9 is an enlarged sectional view of the first embodiment. Setting values So, S1. of the third embodiment and the conventional structure. The S2 characteristic diagram and FIG. 1O are overall sectional views of the conventional device. 1... Compressor, 8... Non-rotary wobble (swash plate), ■... Movable plate, 6... Hollow bell,
46...First return spring, Hu...Wcz return spring, Group...Electromagnetic actuator (set value control means), Ku...Motor (set value control means). Fig. 1 48...・ 2119-ance 7°〉tsu' Fig. 4 49...q !?1in 50... Electromagnetic 7 Riko Uni=9 51... Plunger Fig. 6 Fig. 7 Figure 56...Shift 57...Rack 58...7-9 59...Gonio>

Claims (1)

[Claims] 1. In a structure in which a control valve is provided inside the compressor of an air conditioner that performs variable capacity control using the pressure behind the swash plate and that operates based on a predetermined set value to control the pressure, the discharge pressure of the compressor A compressor structure for a vehicle air conditioner, characterized in that a set value control means is provided for changing and controlling the set value accordingly.