JPS6411868B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a rotary type directional valve.

A conventional rotary-type directional switching valve, in which a rotor is rotatably provided in a housing, a plurality of switching holes are provided in the housing, and switching grooves are provided in the rotor, and the conduction between the switching holes is controlled by the switching groove of the rotor. This is done by

However, in conventional switching valves, the pair of switching grooves located symmetrically with respect to the rotation center of the rotor do not have the same groove width with the inner periphery of the housing. Even if the pressure of the fluid is the same, the widths of the switching grooves are different, so the forces acting in the circumferential direction are different, and the rotor is pressed against the housing. (The direction in which it is pressed differs depending on the shape of each switching groove.) This causes problems such as an increase in the rotational torque of the rotor and locking. Furthermore, if the end face of the switching groove of the rotor touches the switching hole provided in the housing, the pressure of the working fluid acting on the switching hole will act on the outer periphery of the rotor that overlaps the switching hole of the housing. The pressure balance acting on the rotor in the circumferential direction is disrupted and the rotor is pressed against the circumference of the housing, causing problems such as increased rotor rotational torque and rotor locking. Even if there are
It also occurs when rotating.

In view of the drawbacks of the prior art, an object of the present invention is to balance the circumferential force acting on the rotor in any case, and as a result, to suppress the rotor rotational torque to a low level and improve the lock prevention function. The purpose of this invention is to propose a rotary type directional control valve.

The following will be explained with reference to the drawings. In FIG. 1, reference numeral 10 shows the rotary type directional control valve as a whole according to the present invention, which includes a cylindrical housing 12 and a rotor 14 rotatably provided within the housing 12. It is a basic component. The housing 12 is fitted and fixed to the valve body 16. The housing 12 has a plurality of (four in the figure) switching holes 121a,
121b, 121c, and 121d, and are connected to the oil feed pipe 20a, the switching pipes 20b, 20c, and the oil drain pipe 20d, which are attached to the valve body 16, respectively. The conduction between these tubes is controlled by the rotation of the rotor 14, as will be described later.

Two pairs of switching grooves 141a and 141 on the rotor 14
b, and 142a and 142b, and in either case, the pair of switching grooves are provided point-symmetrically with respect to the rotation center O of the rotor. Switching grooves 141a and 141b symmetrical at each point, and 142a and 142b
are communication holes 143 and 1 formed in the rotor, respectively.
44 and communicate with each other. What should be noted is that the switching grooves 141a, 141b, 142a14 are symmetrical at each point.
2b has a groove width formed with the inner circumference of the housing 12.
They are equal as L ₁ and L ₂ .

According to the present invention, the housing 12 has a balance hole 1 at a point symmetrical position with respect to the rotation center O of each switching hole 121a, 121b, 121c, 121d.
24a, 124b, 124c, and 124d.

In the illustrated embodiment, the rotary switching valve 10 is used to drive the cylinder 40. The oil feed pipe 20a is connected to a hydraulic pump 44 via an oil feed pipe 42. The switching pipe 20b is connected to a lower hydraulic chamber 50 of the piston 48 of the cylinder 40 via a pipe 46. Switching tube 2
0c is connected to the upper hydraulic chamber 54 of the piston 48 via a pipe 52. Further, the oil drain pipe 20d returns to the tank 58 via an oil drain pipe 56. Note that 60 is a relief valve.

To describe the operation of the present invention as described above, assuming that the rotor 14 is now in the angular position shown in FIG. 1, the oil pump 44 pumps the oil in the tank 58 to the pipe 42. The relief valve 60 regulates the pressure of the pumped oil to a specified level, and the remaining oil is returned to the tank 58. Oil enters the oil feed pipe 20a from inside the pipe 42, passes through the switching hole 121a of the rotary switching valve 10, the switching groove 141a of the rotor 14, and the switching hole 121b, flows into the switching pipe 20b, and flows into the switching pipe 20b via the pipe 46 to the lower oil of the hydraulic cylinder 40. It flows into the chamber 50 and forces the piston 48 upward as shown. Here, oil flowing into the switching groove 141a passes through the communication hole 143 to the switching groove 141b and the balance holes 124a, 124b.
It acts on The switching grooves 141a and 141b are point symmetrical with respect to the rotation center O, and the housing 14
The groove width with respect to the inner circumference is also the same as _L1 . As a result, the applied hydraulic pressure is also the same, and therefore the circumferential hydraulic pressure applied to the rotor 14 from the switching grooves 141a and 141b is balanced. On the other hand, oil in the upper oil chamber 54 of the hydraulic cylinder 40 enters the switching pipe 20c due to the rise of the piston 48, and enters the switching hole 121.
c, switching groove 142a, communication hole 144, switching groove 14
2b, a drain oil pipe 5 for drain passing through the switching hole 121d
6 to the oil tank 58. Here, the positions of the switching grooves 142a and 142b of the rotor 14 are point symmetrical with respect to the rotation center O, and the groove width with respect to the inner circumference of the housing is common, such as _L2 .
Therefore, from the switching grooves 142a and 142b, the rotor 1
The circumferential hydraulic pressures that 4 receive are balanced.

Next, the rotor 1 is rotated by a rotational drive mechanism (not shown).
4 is rotated to the position shown in FIG.
1a, switching groove 141a, communication hole 144, switching groove 1
41b, the switching hole 121c, and the switching pipe 20c to enter the upper oil chamber 54 and drive the piston 48 downward.
The oil in the lower oil chamber 50 is supplied to the switching hole 1 from the switching pipe 20b.
21b, the switching groove 142a, the communication hole 143, the switching groove 142b, the switching hole 121d, and the oil drain pipe 20d. In this case as well, for the same reason as stated above, the rotor 1
The circumferential force acting on 4 is balanced.

Further, although FIG. 3 shows a state in which the rotor switches between the positions shown in FIG. 1 and FIG. 2 during rotation, the above-described pressure balance is maintained in the present invention even in this case. That is, the hydraulic pressure acting on the rotor 14 includes the force due to the hydraulic pressure acting on the switching groove 141a and the switching hole 121.
The sum of the hydraulic forces acting on the rotor outer circumference portion 146a applied to the switching hole 121a is the sum of the hydraulic forces acting on the rotor outer circumference portion 146a, but the rotor outer circumference portion 146b is also applied to the balance hole 124a, which is located symmetrically with the switching hole 121a, and the area of 146a and 146b is Since the positions are equally point symmetrical, the hydraulic forces are equal, and the hydraulic forces in the circumferential direction of the rotor are balanced out. Also, a portion 146c of the outer periphery of the rotor 14 covering the switching hole 121d and a portion 146 of the outer periphery of the rotor 14 covering the balance hole 124d.
Since the areas of d are equal and the positions are point symmetrical, the hydraulic forces are equal, and the hydraulic forces in the circumferential direction of the rotor are balanced out.

As described above, in the present invention, the force due to the hydraulic pressure acting on the rotor is balanced in the circumferential direction at any position on the rotor. Therefore, the rotor 14 rotates extremely smoothly even with a small torque and does not lock.

In the embodiment shown in FIG. 4, the switching holes 221a, 22
The positions of 1b, 221c, and 221d are different.
Others are the same. That is, a pair of switching grooves 2 of the rotor
41a and 241b, 242a and 242b are provided symmetrically and have the same groove width, and are mutually connected to the communication hole 24.
3,244. Also, the switching hole 221
Balance holes 224a, 224b, 224c, 224 are symmetrical with a, 221b, 221c, 221d.
d is provided. The action and effect are also unchanged.

Note that the balance hole maintains the balance of the force caused by the working fluid pressure, so if only a small amount of pressure is always acting on a specific switching hole, a balance hole is not necessarily required at a point symmetrical to that switching hole. Sometimes.

As described above, according to the present invention, no matter what rotational position the rotor is in, the hydraulic force acting on the portion of the outer peripheral surface of the rotor facing the rotor rotation center is always balanced, so that the rotor The rotor is not pressed against one side of the inner wall of the housing, so the rotor can rotate smoothly with a small torque.

In addition, the balance hole provided in the housing is independent of the pipe through which the working fluid flows in and out, that is, it is not connected to it, so no extra space is required for this pipe, and the entire valve device can be made smaller. I can do it.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the first position of the switching valve of the present invention, FIG. 2 is a diagram showing the second position, and FIG. 3 is a diagram showing the first position.
A diagram showing an intermediate position between the figure and FIG. 2, FIG. 4 is another embodiment, 12...Housing, 14...Rotor, 121
a, 121b, 121c, 121d... switching hole,
124a, 124b, 124c, 124d...Balance groove, 141a, 141b, 142a, 14
2b...Switching groove, 143, 144...Communication hole.

Claims (1)

[Claims] 1 Consisting of a housing and a rotor that rotates within the housing, the housing has a plurality of switching holes on its inner periphery through which working fluid flows through pipes, and the rotor has a plurality of switching grooves on its outer periphery. In the rotary type directional switching valve, the switching groove of the rotor is located at a point symmetrical with respect to the center of rotation of the rotor. The pair of switching grooves, which are formed in symmetrical positions, have the same width with respect to the inner periphery of the housing, and are communicated with each other through a communication hole provided in the rotor. A rotary shape direction characterized in that balance holes having the same shape as the switching holes are formed at point-symmetrical positions with respect to the rotor rotation center of these switching holes, and each of these balance holes is independent of a pipe through which working fluid flows in and out. switching valve.