JPS6123667Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a two-speed control device for a swash plate type variable axial plunger pump motor.

The swash plate type variable axial plunger pump/motor changes its capacity by rotating the tilt drive shaft integrated with the swash plate and tilting the swash plate.
Two speeds, for example, high-speed and low-speed speed control are now available. In this high-speed/low-speed speed control, high-speed operation means high-discharge operation for pumps and low-suction operation for motors, and low-speed operation means low-speed operation for pumps. In the case of a motor, this means a small discharge amount operation, and in the case of a motor, a large suction amount operation.

In the above swash plate type variable axial plunger pump/motor, for example, in the case of a pump, when the swash plate is operated at high speed (large discharge amount operation), the positional relationship between the low and high pressure ports of the valve plate changes. A force acts on the swash plate to return it to low speed operation (small discharge amount operation), and in the case of a motor, when the swash plate is similarly brought into high speed operation (small suction amount operation), As in the above case, a force acts on the swash plate to return it to the low speed operation (large suction amount operation) direction due to the positional relationship of the low and high pressure ports of the valve plate.

An example of the above operation will be explained with reference to FIGS. 3 to 6.

In FIG. 3, when the rotating shaft a rotates in the direction of the arrow, the valve plate b moves from i to
The area between ``B'' is a low pressure port for a pump and the high pressure port for a motor, and the area between ``H'' and ``D'' is a high pressure port for a pump and a low pressure port for a motor, and between ``A'' and ``D'' is a low pressure port for a motor. I am repeatedly inhaling and exhaling. The pressure generated by this repeated action of suction and discharge is transmitted from the piston c to the swash plate d and then to the tilted drive shaft e, and rotational force acts on the tilted drive shaft e.

The pressure situation acting on the valve plate b is shown in FIGS. 5 and 6 with the swash plate d being replaced.

First, in the case of a pump, if the same low pressure is generated between C and D and the same high pressure is generated between A and B with respect to the center line of the tilted drive shaft e, the whole will be balanced. Although no rotational force is generated around the tilt drive shaft 3e, residual pressure is actually generated between F when switching from high pressure to low pressure, and this pressure is the force that rotates the swash plate d in the direction of small displacement, that is, In FIG. 6, a force in the direction of arrow H acts on swash plate d.

In the case of a motor, the above action is opposite, the pressure between C and D is high, the pressure between A and B is low, and residual pressure is generated between G, which switches from high pressure to low pressure, and this pressure increases the slope d. The force that rotates in the capacitive direction, that is, the sixth
In the figure, a force in the direction of arrow I acts on swash plate d.

In this way, depending on the positional relationship between the low and high pressure boats of the valve plate b, a rotational force is applied to the swash plate d, which tends to rotate in the direction of a small discharge amount in the case of a pump and in the direction of a large suction amount in the case of a motor. do.

Therefore, in the case of the above-mentioned pump/motor, the inclined drive shaft e may be rotated to maintain the high speed operation state, for example, in the case of a pump, or the inclined drive shaft e may be rotated.
A holding force must be applied to overcome the rotating force in the return direction.

Previously, a hydraulic servo mechanism was used to provide this kind of holding force to the tilting drive shaft, but this had the drawback of making the structure of the variable axial plunger pump/motor complex and increasing costs. .

The present invention was developed in consideration of the above-mentioned issues, and it is possible to simplify the structure of a variable axial plunger pump motor and reduce costs compared to the case where a conventional hydraulic servo mechanism is used. It is an object of the present invention to provide a two-speed control device for a variable axial plunger pump/motor.

Embodiments of the present invention will be described below based on the drawings. In this embodiment, a case of a pump will be described.

In the figure, 1 and 2 are a pair of variable axial plunger pumps that have the same symmetrical configuration and are installed at intervals on the same axis, and 3 and 4 are respective inclined drive shafts. , 4 to levers 5, 6
When the levers 5 and 6 of both shafts 3 and 4 are rotated inwardly (in the direction of the solid arrow) by the rods 7 and 8, both pumps move at high speed and in the outward direction ( (in the direction of the dotted arrow)
Each is controlled to a low speed when rotated. The other ends of the rods 7 and 8 are connected to a plate 9. The connection points 7a and 8a between the rods 7 and 8 and the plate 9 are connected to the connection point 7b between the rod 7 and the lever 5, and the connection point 7b between the rod 8 and the lever 6.
The rods 7, 8 are located at a position deviated downward from the line connecting the connecting point 8b with the levers 5, 7, and the rods 7, 8 are located in the tangential direction of the rotation circle of each lever 5, 7. An actuating rod 10 is located between the connection points 7a and 8a of the plate 9.
One end of the actuating rod 10 is connected, and the other end of the actuating rod 10 is connected to a rotating lever 11a fixed to a rotating shaft 11. This actuating rod 10 has an apex angle 2θ formed by the rods 7 and 8 connected to the levers 5 and 6.
The plate 9 is movable in the direction of this bisector. The rotation shaft 11 is provided with an operating lever 12 and a toggle link 13. A spring 14 is attached to the toggle link 13 so that the toggle link 13 biases the rotation shaft 11 on both sides of the dead center which coincides with the rotation axis. The positional relationship between this toggle link 13 and the plate 9 is such that when the operating lever 12 is rotated and the toggle link 13 is rotated to one of the dead centers, the plate 9 moves downward via the rod 10, and the other The plate 9 is configured to move upward when the plate 9 is rotated. Note that the angle θ between the actuating rod 10 and the mouths 7 and 8 is relatively large, and is approximately 60 degrees.

In the above configuration, when the operating lever 12 is rotated in one direction, the plate 9 moves downward in the drawing, and this movement of the plate 9 pulls the rods 7 and 8 inward, and the levers 5 and 6 connected to each other move inward. The variable axial plunger pumps 1 and 2 are set at high speed positions. When the operating lever 12 is rotated in the other direction against the toggle link 13, the plate 9 moves upward in the drawing, and the rods 7, 8 are pushed outward, causing the levers 5,
6 rotates outward, and each motor 1, 2 is set to a low speed position.

On the other hand, when both the pumps 1 and 2 are set at the high speed position, a force is applied to switch them in the opposite direction, and rotational force is applied to the levers 5 and 6. , 8, the force P acting on the actuating rod 10 becomes a component of the force F acting on the levers 5, 6 and becomes smaller.
1 is sufficiently supported by the spring 14 of the toggle link 13, and the rotation shaft 11 is not rotated from the levers 5 and 6 side.

In the above embodiments, a pump has been described, but the same applies to a motor.

The two-speed control device for a variable axial plunger pump/motor according to the present invention is as described above, and the variable axial plunger pump/motor is controlled to switch between high speed and low speed by reciprocating the tilt drive shafts 3 and 4. In axial plunger pumps and motors,
Levers 5, 6 fixed to the tilt drive shafts 3, 4
One end of the rods 7, 8 is connected to the plate 9, the other end of which is reciprocated in one direction by a rotating shaft 11 that is rotated by an operating lever 12. The rods 7 and 8 are connected so that their axes substantially coincide with the rotating direction of the levers 5 and 6 and form a predetermined angle θ with respect to the moving direction of the plate 9, and the reciprocating movement of the plate 9 moves the rods 7 and 8. The tilt drive shafts 3 and 4 are switched between a low speed position and a high speed position through the rotary shaft 11.
A configuration in which toggle links 13 are connected so that when the plate 9 is rotated in one direction beyond the dead center against a spring force, the plate 9 is moved to one side, and when the plate 9 is rotated to the other side, the plate 9 is moved to the other side. Therefore, the inclined drive shafts 3 and 4 in the low speed position or the high speed position
Even if a force is applied to rotate the plate 9 to the opposite speed position, the force that tries to move the plate 9 connected to the rotation shaft 11 becomes smaller, and furthermore, this reduced force is applied to the toggle link 13. The inclined drive shafts 3 and 4 of the variable axial plunger pump motors 1 and 2 are held in a stable state at a predetermined rotational position by being pressed by a spring. Therefore, compared to the case where a conventional hydraulic servo mechanism is used, the structure of the variable axial plunger pump/motor can be simplified and the cost can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a configuration explanatory diagram showing an embodiment of the present invention, Fig. 2 is a partially cutaway side view, and Figs. 3 to 6 are for explaining the state of pressure acting on the valve plate. FIG. 3 is a cutaway perspective view showing the configuration of the variable axial plunger pump/motor, FIG. 4 is an exploded perspective view of the main parts, FIG. 5 is a front view of the valve plate, and FIG. FIG. 1 and 2 are variable axial plunger pump motors, 3 and 4 are tilt drive shafts, 5 and 6 are levers,
7 and 8 are rods, 9 is a plate, 11 is a rotation axis,
12 is an operating lever, and 13 is a toggle link.

Claims (1)

[Scope of utility model registration request] By reciprocating the tilt drive shafts 3 and 4,
In the variable axial plunger pump/motor 1, 2 which is controlled to switch between two speeds, the levers 5, 6 fixed to the tilting drive shafts 3, 4,
Connect one end of rods 7 and 8, and
A rotating shaft 1 whose other end is rotated by an operating lever 12
Plate 9 configured to reciprocate in one direction at 1
The rods 7 and 8 are connected so that their axes substantially coincide with the rotating direction of the levers 5 and 6 and form a predetermined angle θ with respect to the moving direction of the plate 9, so that the rods are moved by the reciprocating movement of the plate 9. 7 and 8, the tilting drive shafts 3 and 4 are rotated to switch between two speed positions, and when the rotation shaft 11 is rotated in one direction beyond the dead center against the spring force. When the plate 9 is moved to one side and rotated to the other side, the plate 9
A two-speed control device for a variable axial plunger pump/motor, characterized in that the variable axial plunger pump/motor is connected with a toggle link 13 that moves one to the other.