JP2004324543A - Variable displacement pump control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable displacement pump control device with a simplified electric circuit capable of lowering power consumption in an electromagnetic clutch. <P>SOLUTION: This variable displacement pump control device comprises a variable displacement pump 100 having the electromagnetic clutch 130 to transmit and stop transmitting driving force from an external drive source and a solenoid valve 150 to change the discharge amount per revolution by opening and closing a valve 151, and a control device 200 to control the engagement and disengagement of the clutch 130 and the opening degree of the solenoid valve 150 via a switching element 210 for changing the amount of current to be supplied based on an output signal. The discharge amount of the variable displacement pump 100 is so set to become larger as the amount of current increases, and the electromagnetic clutch 130 and the solenoid valve 150 are electrically connected to one switching element 210. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a variable displacement pump control device suitable for application to a vehicle cooling device.
[0002]
[Prior art]
As a conventional technique, for example, a control device for a variable displacement pump as disclosed in Patent Document 1 is known. In this control device, the variable displacement pump is provided with an electromagnetic clutch for interrupting the transmission of driving force from an external drive source such as an engine, and an electric actuator for controlling the displacement, and the electromagnetic clutch and the electric actuator are controlled by an electric control circuit. Operation is controlled. Here, when the discharge capacity of the variable displacement pump is changed to a smaller value, the current supplied to the electromagnetic clutch is reduced in conjunction with the change, so that the power consumption of the electromagnetic clutch can be reduced. .
[0003]
[Patent Document 1]
JP-A-60-233385
[Problems to be solved by the invention]
However, there is no correlation between the currents supplied to the electromagnetic clutch and the electric actuator, and relays for the electromagnetic clutch and the electric actuator are provided in the electric circuit, and the current value to the electromagnetic clutch is varied. In addition, a circuit switching relay, a current limiting resistor, and the like are required, which is costly.
[0005]
In view of the above problems, an object of the present invention is to provide a variable displacement pump control device capable of simplifying an electric circuit while reducing power consumption by an electromagnetic clutch.
[0006]
[Means for Solving the Problems]
The present invention employs the following technical means to achieve the above object.
[0007]
According to the first aspect of the present invention, the variable displacement having the electromagnetic clutch (130) for interrupting the driving force from the external drive source and the electromagnetic valve (150) for varying the discharge displacement per rotation by opening and closing the valve (151). A control device for controlling the on / off state of the electromagnetic clutch (130) and the opening degree of the electromagnetic valve (150) via the mold pump (100) and the switching element (210) for varying the amount of current to be supplied according to the output signal (200), the discharge capacity of the variable displacement pump (100) is set so as to increase as the amount of current increases, and the electromagnetic clutch (130) and the solenoid valve ( 150) is characterized by being electrically connected to one switching element (210).
[0008]
As a result, the amount of current supplied to the electromagnetic clutch (130) increases or decreases in accordance with the increase or decrease in the discharge capacity of the variable displacement pump (100), so that the current supply from one switching element (210) And the electric circuit can be simplified. At this time, as the discharge capacity decreases, the amount of current to the electromagnetic clutch (130) also decreases, so that the electromagnetic clutch (130) can have an attraction force corresponding to the discharge capacity (drive torque), so that consumption is reduced. The power can be reduced.
[0009]
According to a second aspect of the present invention, in the relationship between the discharge capacity and the current amount, the current amount has a predetermined value when the discharge amount is zero.
[0010]
Accordingly, when the discharge capacity is zero, a minimum amount of attraction force can be generated in the electromagnetic clutch (130) with a current amount corresponding to a predetermined value. ) Does not slip.
[0011]
Note that the reference numerals in parentheses of the above means indicate the correspondence with specific means described in the embodiment described later.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
(1st Embodiment)
1 to 3 show a first embodiment of the present invention. First, a specific configuration will be described. The variable displacement pump control device 10 is applied as a variable displacement pump to a variable displacement compressor 100 disposed in a refrigeration cycle of an automobile cooling device. The operation is controlled by the device 200.
[0013]
The variable displacement compressor (hereinafter, compressor) 100 compresses the refrigerant in the refrigeration cycle so that the discharge capacity thereof is variable, and mainly includes a pulley 120, an electromagnetic clutch 130, a compressor unit 140, and an electromagnetic valve 150. .
[0014]
The pulley 120 is rotatably supported by a pulley bearing 121 fixed to the front housing 111, and the driving force of an engine as an external drive source (not shown) is transmitted via a belt (not shown) and is driven to rotate. I have. The drive shaft 122 is provided at the center of the pulley 120, extends toward a compressor 140 described below, and is rotatably supported by a bearing 123 fixed to the front housing 111 and a bearing 124 fixed to the middle housing 112. Have been.
[0015]
The electromagnetic clutch 130 forms an intermittent mechanism for intermitting the driving force transmitted from the pulley 120 to the drive shaft 122, and includes a coil 131 fixed to the front housing 111 and a hub 132 fixed to the distal end of the drive shaft 122. Consisting of As is well known, when the coil 131 is energized, the hub 132 is attracted to the pulley 120 to transmit the driving force of the pulley 120 to the drive shaft 122 (clutch ON). Then, as the current supplied to the coil 131 increases, the attraction force increases. Conversely, when the power supply to the coil 131 is cut off, the hub 132 separates from the pulley 120, and the driving force of the pulley 120 is disconnected (clutch OFF).
[0016]
The compressor section 140 has a discharge capacity per rotation as a discharge amount that can be varied by a solenoid valve 150 and a control device 200, which will be described later. Here, the compressor section 140 is a well-known swash plate type variable displacement compressor section. Specifically, the drive shaft 122 is provided with a swash plate 142 that rotates together with the drive shaft 122, and the tilt angle θ can be changed by a hinge mechanism 143. The swash plate 142 is provided in a swash plate chamber 112a formed by the front housing 111 and the middle housing 112. A plurality of pistons 146 sliding in a cylinder 145 formed in the middle housing 112 are connected to a shoe 144 provided on an outer peripheral portion of the swash plate 142.
[0017]
A rear housing 114 is provided on the side opposite to the pulley of the middle housing 112 via a valve plate 113, and the inside of the rear housing 114 is partitioned into a suction chamber 114a and a discharge chamber 114b. The suction chamber 114a communicates with the inside of the cylinder 145 through a suction port 113a provided in the valve plate 113, and the inside of the cylinder 145 communicates with the discharge chamber 114b through a discharge port 113b provided in the valve plate 113. . The suction port 113a and the discharge port 113b are provided with a suction valve and a discharge valve (not shown) so that the piston 146 slides to suck and discharge the refrigerant.
[0018]
The rear housing 114 is provided with an electromagnetic valve 150. A valve element (valve) 151 that slides when the coil 152 is energized is provided in the solenoid valve 150. A communication passage 153 and a communication passage 154 are provided between the discharge chamber 114b and the swash plate chamber 112a via the valve body 151. Further, an exhaust passage is provided between the swash plate chamber 112a and the suction chamber 114a. 155 are provided. When the valve element 151 slides, the valve opening between the two communication passages 153 and 154 is changed, so that communication or cutoff between the discharge chamber 114b and the swash plate chamber 112b is performed. Here, as the amount of current to the coil 152 increases, the valve body 151 operates to close the space between the two communication passages 153 and 154.
[0019]
Further, the relationship between the amount of current to the coil 152 and the discharge capacity of the compressor unit 140 will be described. When the amount of current to the coil 152 is small, the valve element 151 is held on the side that opens the two communication passages 153 and 154, and the pressure Pd of the discharge chamber 114b is distributed to the swash plate chamber 112a, and the pressure in the swash plate chamber 112a is Pc is increased. Then, the inclination angle θ of the swash plate 142 becomes small (rises perpendicularly to the drive shaft 122), and the stroke of the piston 146 is made small to reduce the discharge capacity.
[0020]
On the other hand, when the amount of current to the coil 152 increases, the valve body 151 slides to the side that closes the two communication passages 153 and 154, and the distribution of pressure from the discharge chamber 114b to the swash plate chamber 112a is stopped. . On the other hand, the pressure is released from the swash plate chamber 112a to the suction chamber 114a through the exhaust passage 155, and the pressure Pc in the swash plate chamber 112a decreases. Then, the inclination angle θ of the swash plate 142 increases (inclines toward the drive shaft 122), and the stroke of the piston 146 increases to increase the discharge capacity.
[0021]
The control device 200 is based on an A / C request signal input by an occupant, a target temperature (Teo) signal determined by a set temperature signal, an evaporator temperature (Te) signal obtained from a temperature sensor behind the evaporator in the refrigeration cycle, and the like. Thus, the on / off state of the electromagnetic clutch 130 and the opening degree of the electromagnetic valve 150 are controlled.
[0022]
The control device 200 includes a transistor (the present invention) that varies the ratio of the ON-OFF time of the output current to vary the magnitude of the average current according to the output signal (duty ratio) output from the control device 200. ) 210 is provided. The transistor 210 is connected to the coil 131 of the electromagnetic clutch 130 and the coil 152 of the electromagnetic valve 150 so that a control current is supplied to both coils.
[0023]
Here, as shown in FIG. 3, the discharge capacity of the compressor 100 with respect to the duty ratio output from the control device 200 is set to zero at a duty ratio of 50% (corresponding to a predetermined value of the current amount in the present invention). The discharge capacity is set to 100% at a duty ratio of 100%. That is, when the amount of current supplied from the transistor 210 corresponds to a duty ratio of 50%, the valve element 151 of the solenoid valve 150 maintains the open state between the two communication paths 153 and 154, and makes the discharge capacity almost zero. When the amount of current supplied from the transistor 210 is equivalent to a duty ratio of 100%, the valve element 151 completely closes the space between the two communication paths 153 and 154, and the discharge capacity is maximized.
[0024]
It should be noted that the magnitude of the amount of current supplied from the transistor 210 to the coil 131 of the electromagnetic clutch 130 varies depending on the electromagnetic valve 150.
[0025]
Next, an operation based on the above configuration will be described. First, when there is an A / C request signal from an occupant, control device 200 turns on electromagnetic clutch 130 and operates compressor unit 140 by the driving force of the engine. Then, the discharge capacity is varied by the solenoid valve 150 so that the evaporator temperature Te becomes the target temperature Teo. If the evaporator temperature Te is higher than the target temperature, the discharge capacity is increased (the amount of current to the coil 152 is large), and as the evaporator temperature Te approaches the target temperature Teo, the discharge capacity is reduced (the amount of current to the coil 152 is reduced). ) Is done. When the evaporator temperature Te becomes equal to or lower than the target temperature Teo, the discharge capacity is maintained at substantially zero (the current amount of 152 to the coil corresponds to a duty ratio of 50%). While the discharge capacity is varied in this way, the amount of current supplied to the coil 131 of the electromagnetic clutch 130 also corresponds to the solenoid valve 150 side, and the suction force according to the discharge capacity of the compressor unit 140 is reduced. Will be generated. If there is no A / C request signal, control device 200 turns off electromagnetic clutch 130 and stops compressor unit 140.
[0026]
In the present invention, since the amount of current supplied to the electromagnetic clutch 130 increases or decreases in accordance with the increase or decrease in the discharge capacity of the compressor 100, the current from one transistor 210 to the electromagnetic clutch 130 and the electromagnetic valve 150 Supply is possible, and the electric circuit can be simplified.
[0027]
At this time, as the discharge capacity decreases, the amount of current to the electromagnetic clutch 130 also decreases, so that the electromagnetic clutch 130 can have an attraction force corresponding to the discharge capacity (drive torque), thereby reducing power consumption. be able to.
[0028]
When the discharge capacity is zero, the electromagnetic clutch 130 can generate a minimum attraction force with a current amount corresponding to a predetermined value. Therefore, even when the discharge capacity increases, the electromagnetic clutch 130 may slip. There is no.
[0029]
(Other embodiments)
In the embodiment described above, the variable displacement pump is described as being applied to the variable displacement compressor 100 in the refrigeration cycle. However, the present invention is not limited to this. As long as the discharge capacity is increased, the present invention may be applied to a power steering pump or the like.
[0030]
Further, the supply current amount at the discharge capacity of zero is not limited to the duty ratio equivalent to 50%, and may be determined as a value in consideration of the characteristics of the compressor 100 and the required suction force of the electromagnetic clutch 130.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing the overall configuration of the present invention.
FIG. 2 is a circuit diagram showing a connection state between a transistor in FIG. 1 and a coil of an electromagnetic clutch and an electromagnetic valve.
FIG. 3 is a graph showing a relationship between a duty ratio from a control device and a displacement of a compressor.
[Explanation of symbols]
10 Variable displacement pump control device 100 Variable displacement compressor 130 Electromagnetic clutch 150 Solenoid valve 151 Valve body (valve)
200 Control device 210 Transistor (switching element)

Claims (2)

A variable displacement pump (100) having an electromagnetic clutch (130) for intermittently driving a driving force from an external drive source and an electromagnetic valve (150) for varying a discharge capacity per rotation by opening and closing a valve (151);
A control device (200) for controlling the on / off of the electromagnetic clutch (130) and the valve opening of the electromagnetic valve (150) via a switching element (210) for varying the amount of current to be supplied according to the output signal; In the variable displacement pump control device having
The discharge capacity of the variable displacement pump (100) is set so as to increase as the current amount increases,
The variable displacement pump control device, wherein the electromagnetic clutch (130) and the electromagnetic valve (150) are electrically connected to one switching element (210). 2. The variable displacement pump control device according to claim 1, wherein in the relationship between the discharge capacity and the current amount, when the discharge capacity is zero, the current amount has a predetermined value. 3.

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