JP2554930B2 - Hydraulic pump device - Google Patents

Description

The present invention relates to a hydraulic pump device suitable for use in an injection molding machine, a transfer machine, a die cast machine, or the like.

[Conventional technology]

Conventionally, a fluid control device for variably controlling the discharge amount of a variable discharge pump by a control signal is disclosed in, for example, Japanese Patent Laid-Open No. 62-270803.
No. 1993, which is hereby incorporated by reference.

By the way, since such a fluid control device drives an operation piston (control cylinder) for displacing the swash plate by utilizing a part of the pressure oil discharged from the variable discharge pump itself, depending on the control state of the variable discharge pump. There is a problem that a difference in response speed occurs, a highly accurate control system cannot be configured, and in the case of an actuator or the like having a small load pressure, control cannot be performed.

Therefore, the applicant has already filed Japanese Patent Application No. 1-12139,
By providing an auxiliary pump with an independent hydraulic circuit system to the variable discharge pump, the operation piston can be driven, and thus a fluid control device with improved control accuracy, responsiveness, and stability is provided. Proposed.

[Problems to be Solved by the Invention]

However, since the fluid control device using the auxiliary pump requires two pumps, that is, a variable discharge pump and an auxiliary pump, these two pumps are usually arranged side by side and one motor is used for the variable discharge pump. The rotary shafts of the variable discharge pump and the auxiliary pump are connected to each other by a rotation transmission mechanism, and the pumps are simultaneously operated.

For this reason, a large installation space is required for installing the two pumps, and there are problems to be solved such as a disadvantage in terms of cost and assembly.

The present invention has an object to provide a hydraulic pump device that solves the problems existing in such conventional techniques.

[Means for solving the problem]

According to the present invention, when the hydraulic pump device 1 in which the variable discharge pump 2 having the rotating shaft 4 is built in the casing 3, the space P is formed in the casing 3, and the rotating shaft 4 is formed in the space P. By arranging the vane type auxiliary pump 6 that drives the control cylinder 5 that changes the swash plate angle of the variable discharge pump 2 and forms the connection end surface 31 on the outer surface of the casing 3, A control valve 8 is attached to the connection end face 31, and further,
The casing 3 has a port 34 for oil supply for connecting the auxiliary pump 6 and the control valve 8, the control valve 8 and the control cylinder 5.
It is characterized in that ports 27 and 28 for connecting with each other are formed.

[Action]

 Next, the operation of the present invention will be described.

According to the hydraulic pump device 1 of the present invention, two pumps, that is, the variable discharge pump 2 and the vane type auxiliary pump 6, are built in the casing 3, and one rotary shaft 4 is provided.
Since both of the pumps 2 and 6 are shared by rotating the rotary shaft 4 with the motor 12, the pumps 2 and 6 can be operated simultaneously.

On the other hand, the pressure oil discharged from the auxiliary pump 6 is the casing 3
A control valve 8 attached to a connection end surface 31 on the outer surface of the pump is supplied to a control cylinder 5 of a variable discharge pump 2 through a port formed in the cylinder 3 to change the angle of a swash plate 22 in the pump 2. Thus, the discharge amount of the pump 2 can be variably controlled.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

First, the configuration of the hydraulic pump device 1 according to the present invention will be described with reference to FIG.

The hydraulic pump device 1 integrates a variable discharge pump (hereinafter referred to as a main pump) 2 using a piston type pump driven by a motor 12 (see FIG. 2) and an auxiliary pump 6 using a vane type pump. Configure.

Reference numeral 3 denotes a casing, which includes a tubular casing portion 3a and a lid-shaped casing portion 3b. The casing 3 is provided with a rotating shaft 4 which is rotatably supported by bearings 16 and 17 and which is shared by the main pump 2 and the auxiliary pump 6,
The rotating shaft 4 is rotated by the motor 12. A cylinder block 20 in which a plurality of cylinders 19 ... Is sequentially formed at regular intervals in the shaft circumferential direction is attached to a rotary shaft 4 in a casing 3, and pistons 21 ... Are slidably inserted into each cylinder 19. The tip of each piston 21 is swingably connected to the end face of a swash plate 22 formed in the shape of a ring plate via a ball joint. The swash plate 22 is rotatably guided by a guide board 23, and one end of the guide board 23 at a 180-degree facing position abuts on the tip of an operation piston 24 inserted in the first cylinder 5a constituting the control cylinder 5, And the other end is the second cylinder 5b
It comes into contact with the tip of the bias piston 25 inserted in the. The bias piston 25 is biased by the spring 26 in the direction in which the swash plate 22 is maximally inclined.

Therefore, if pressure oil is supplied to the first cylinder 5a and the operation piston 24 is projected, the swash plate 22 is displaced in the direction perpendicular to the rotary shaft 4, and the operating stroke of each piston 21 is small. Further, the discharge amount of the main pump 2 decreases accordingly, and further becomes zero. Further, if pressure oil is supplied to the second cylinder 5b and the bias piston 25 is projected, the swash plate 22 is more inclined with respect to the rotary shaft 4, so that the working stroke of each piston 21 becomes large,
The discharge amount of the main pump 2 increases.

On the other hand, various ports 27, 28 required for the casing portion 3b,
29b is provided. Of these ports, 27 is the first cylinder 5a, 28 is the second cylinder 5b, 29b is each cylinder 19 ...
And the outer ends of the ports open to the connection end face 31 provided in the casing portion 3b. The discharge port 29a branched from the port 29b communicates with the main circuit 32 (FIG. 2) including various actuators.

On the other hand, a space P is formed inside the casing 3b,
A vane-type pump (auxiliary pump 6) is configured by attaching a rotor 33 having a plurality of vanes slidably to the rotary shaft 4 in the space P. Therefore, the space portion P becomes a circular ring portion of the vane pump. Further, 34 is a discharge port communicating with the auxiliary pump 6, and the tip thereof is open to the connection end face 31. Although not shown in FIG. 1, the oil suction ports of the pumps 2 and 6 are common oil tanks shown in FIG.
Connect to 35.

A control valve 8 is integrally attached to the connection end face 31 via a switching valve 7 described later.

Next, an example of a hydraulic control circuit using the hydraulic pump device 1 according to the present invention will be described with reference to FIG.

First, the main pump 2 is provided with a swash plate angle sensor 36 such as a potentiometer or encoder for detecting the angle of the swash plate 22. The swash plate angle sensor 36 functions as a flow rate sensor and is connected to the controller 9 to calculate the swash plate angle and calculate the discharge amount. Further, the main circuit 32 branches according to the number of actuators to be driven, is connected to the actuators A1 ... Through the switching valves 37 ..., and is equipped with a pressure sensor 38 for detecting the discharge pressure. Connect to the controller 9.

The controller 9 is provided with a microcomputer, and has a comparison calculation function for obtaining a deviation by comparing the detection values obtained from the swash plate angle sensor 36 and the pressure sensor 38 with the set values in the setter group 39, and further, the deviation is set to zero based on the calculation result. It has a control signal output function for outputting a control signal S for performing the operation, a sequence control function, and the like. The setter group 39 sets the set values such as the flow rate, the pressure, and the time for each process in the molding cycle.

The switching valve 7 is provided with pressure oil discharged from the auxiliary pump 6,
It has a function of selectively supplying the pressure oil supplied from the main pump 2 through the port 29b to the control valve 8. The switching valve 7 is connected to the control valve 8 side and the connecting end face 31 as shown in FIG.
The position of the connection port is selected so that the sides are connected, and the control valve 8 and ports for connecting to the cylinders 5a and 5b are provided. The control valve 8 has a function of selectively supplying or shutting off the pressure oil supplied from the switching valve 7 to each cylinder 5a or 5b, and is controlled by the control signal S output from the controller 9.

On the other hand, the discharge port of the auxiliary pump 6 is further connected to the oil tank 35 via the Lilihu valve 40 which functions as a safety valve, and also connected to the auxiliary circuit 41 to drive the actuator A2. In this case, the capacity of the auxiliary pump 6 is selected so that the control of the control cylinder 5 and the control of the actuator A2 can be executed simultaneously. In this way, since the auxiliary pump 6 can be used to drive the control cylinder 5 and the auxiliary circuit 41, for example, in the case of an injection molding machine, when the main pump 2 opens the mold, the auxiliary circuit 41 operates the oil motor. Then, the weighing process can be executed. The connection of the auxiliary circuit 41 is arbitrary, and the auxiliary pump 6 having a relatively small capacity capable of driving only the control cylinder 5 when not used.
Is enough. In the figure, 42 is a pressure reducing valve, 43 is an electromagnetic lift valve, 44 is a flow valve, and 45 is a switching valve.

Next, with respect to the operation of such a hydraulic control circuit, flow rate control for operating the pistons of the actuators A1 ... At a predetermined speed will be described as an example.

First, by operating the motor 12, the rotary shaft 4 is rotated, and the main pump 2 and the auxiliary pump 6 are simultaneously activated. On the other hand, by switching the switching valve 7 to the auxiliary pump 6 side, the pressure oil discharged from the pump 6 is controlled by the control valve 8
Supply to. Then, from the controller 9 to the control valve 8, a flow rate command signal (control signal S) corresponding to the set flow rate.
The control cylinder 5 is driven and controlled so that the discharge amount of the main pump 2 becomes a set flow rate. At this time, if the control valve 8 is in the neutral position, the hydraulic pressure is cut off and the swash plate angle does not change. However, when the control valve 8 is switched to the left symbol position as shown in FIG. The pressure oil is supplied to the second cylinder 5b, the oil of the first cylinder 5a is discharged to the oil tank 35, and the swash plate 22 is tilted and the main pump 2
Increase the discharge amount of. On the other hand, when the control valve 8 is switched to the right symbol position as shown in FIG. 4, the pressure oil from the switching valve 7 is supplied to the first cylinder 5a and the oil in the second cylinder 5b is supplied to the oil tank 35. After being discharged, the swash plate 22 stands up and reduces the discharge amount of the main pump 2.

By switching the switching valve 7 as shown in FIG. 5, a part of the pressure oil discharged from the main pump 2 can be supplied to the control valve 8. In this case, the auxiliary circuit 6 can be independently driven by the auxiliary pump 6.

Although the embodiments have been described in detail above, the present invention is not limited to such embodiments. For example, by connecting the switching valve 7 to the actuator A2 by the auxiliary pump 6.
Although the case where the actuator is driven is illustrated, the switching valve 7 is not necessary when the actuator A2 is not provided. Therefore, “attaching the control valve 8 to the connection end face 31” means that the control valve 8 is attached to the connection end face 31.
It is a concept that includes both a case of directly attaching to the valve and a case of indirectly attaching via the switching valve 7 or the like as in the embodiment. In addition, the detailed configuration and the like can be arbitrarily changed without departing from the scope of the present invention.

〔The invention's effect〕

As described above, according to the present invention, in a hydraulic pump device in which a casing has a variable discharge pump having a rotary shaft, a space is formed in the casing, the rotary shaft is shared in the space, and the variable discharge is provided. A vane-type auxiliary pump that drives a control cylinder that changes the swash plate angle of the quantity pump is provided, and a control valve is attached to the connection end surface by forming a connection end surface on the outer surface of the casing. The casing has an oil feed port that connects the auxiliary pump and the control valve, and a port that connects the control valve and the control cylinder.This greatly expands the control range and applications, and improves control accuracy and response. In addition to the basic effect that can be achieved, the size of the device can be significantly reduced, the installation space can be halved, and the cost and assembly can be reduced. Improvement can be achieved.

[Brief description of drawings]

1 is an internal configuration diagram of a hydraulic pump device according to the present invention, FIG. 2 is a hydraulic circuit diagram of a hydraulic control circuit using the hydraulic pump device, and FIG. 3 is a control valve in the hydraulic control circuit in which a swash plate is used. Fig.4: Hydraulic circuit diagram in the state of switching to the maximum tilt position, Fig.4: Hydraulic circuit diagram in the state of switching the control valve to the minimum tilt position of the swash plate in the hydraulic control circuit, Fig.5: In the hydraulic control circuit The hydraulic circuit diagram of the state which changed the switching valve to the position which drives an actuator with an auxiliary pump. In the drawing, 1: hydraulic pump device, 2: variable discharge pump 3: casing, 4: rotating shaft 5: control cylinder 6: auxiliary pump, P: space 31: connection end face, 27, 28, 29b, 34: port

Claims (1)

(57) [Claims] 1. A rotating shaft (4) attached to a casing (3).
In a hydraulic pump device (1) including a variable discharge pump (2) having a space (P) formed in the casing (3), the rotary shaft (4) is formed in the space (P). And a vane type auxiliary pump (6) for driving a control cylinder (5) for varying the swash plate angle of the variable discharge pump (2),
By forming a connection end face (31) on the outer surface of the casing (3), a control valve (8) is attached to the connection end face (31), and further, the auxiliary pump (6) is attached to the casing (3). ) And the control valve (8) for connecting oil, and ports (27) and (28) for connecting the control valve (8) and the control cylinder (5) are formed. And hydraulic pump device.