JPS58176480A - Piston motor or pump - Google Patents

Abstract

PURPOSE:To control the amount of displacement of the piston by changing only the port of a valve plate by a method wherein at least one of ports provided on the valve plate is provided with a closed part, whose width is same as the same of the port, about a position apart from a lower dead point by a desired angle. CONSTITUTION:The place between the end part 21a of the first port 21 and the end part 22b' of the second port 22' as well as the place betweeen the end part 22b of the second port 22 and the same 21a' of the first port 21' have closed part H1, H1', having widths W1, W1' equal to the width W of the port, about the lower dead point a1 and the upper dead point a1', and the place between the end part 21b of the first port 21 and the same 22a of the second port 22 has a closed part H2, having the width W2 same as the same W of the port substantially, about the position a2 apart from the lower dead point a1 by an angle alpha, while the place between the end part 21b' of the first port 21' and the same 22a' of the second port 22' has the closed part H2', whose width W2' is same as the width W of the port substantially, at the position a2' symmetrical with respect to said position a2 against the center o thereof in the same manner.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a piston motor or pump whose rotational speed or discharge flow rate can be arbitrarily selected as high, low, or large or small by operating a switching valve.

Note that the present invention has similar effects when used with either a piston motor or a piston pump, so only the piston motor will be described. , as shown in FIG. 1 (Japanese Unexamined Patent Publication No. 52-111004), a rotating shaft 2 is rotatably held in a main body 1, and a swash plate 4 having a slope 4a inclined with respect to the rotating shaft 2 is attached to the main body I.
A cylinder block 8, which is shown in an enlarged view in FIG. Port connected to supply/discharge boat 9.10 of main body 1)18.
A pulp plate 7 having a diameter of 19 (FIG. 2(C)) is disposed, and the cylinder block 8 has pistons 5-1 to 5-1 whose one end abuts against the slope 4a via a shoe 12.
Cylinders 6-1 to 6-9 (in which cylinders 5-9 are slidably fitted)
The lower end 4b of the swash plate 4 is configured to be subjected to the pressing forces of both the spring 15 and the piston 16 of the control cylinder 13.

The cylinders 6-1 to 6-9 of the cylinder block 8 are
The end 1fI8alc that the valve plate 7 abuts.

As shown in FIG.
Fix it to the main body 1, as shown in Fig. 2(c),
It has a boat 18.19 connected to the supply/discharge boat 9.10, and the port 18.19 and the passages 6-1' to 6-9' are as follows:
The end face 8a and the valve grate 7 are designed to communicate when they are overlapped. This boat 18.19 has a closed portion Hs, H with a width wtw t / approximately equal to the boat width W, centered on the bottom dead center a 1 r and the top dead center al' of the slope 4a.
It has t'.

The control cylinder 13 has a pressure chamber 17, and is configured to move the piston 16 by L when pressure fluid is supplied to the pressure chamber 17. are connected to a pressure fluid source and a tank, respectively, the cylinder block 8 rotates in the direction of arrow B together with the rotating shaft 2, but at this time, the cylinders 6-1 to 6-1
Pressure fluid is supplied from the boat 18 to each of the passages 6-9 until the centers of the passages 6-1' to 6-9' pass the bottom dead center al in the direction of arrow B and reach the top dead center al'. , top dead center a
Cylinder 6 until it passes l' and reaches bottom dead center al.
-1 to 6-9 fluids flow out to the tank. When the center reaches the top dead center al' and the bottom dead center a1, the passage 6-
1' to 6-9' are all closed by closing portions Hs and Hs'.

When the cylinder block 8 rotates in the direction of arrow B, the swash plate 4 is moved to the position r shown in FIG. )
'LI' as shown in K.

Next, when pressure fluid is supplied to the pressure chamber 17 of the control cylinder 13 and the swash plate 4 is swung by an angle θ around the bottle 3, the interval between the top dead center as/ and the bottom dead center al' becomes small. Therefore, when the cylinder block 8 rotates in the direction of arrow B, the amount of movement of the pistons 5-1 to 5-9 is IJ2 (L2<
Ll). Therefore, the rotational speed of the rotating shaft 2 increases by the amount of decrease in the amount of movement.

In this piston motor, in order to select the rotational speed of the rotating shaft 2, the swash plate 4 is rocked.
Mechanism for controlling the angle of (control cylinder 13, spring 15o
) is required to be provided on the main body 1, which has the disadvantage that the outer shape of the main body 1 is increased or the outer shape of the main body 1 becomes uneven.

Therefore, the technical object of the present invention is to make the outer shape of a piston motor the same as that of a constant speed type piston motor and to be able to arbitrarily select the rotational speed.

The basic configuration of a reservoir for solving this technical problem is that a passage opens in the end face of the cylinder block centered at a position at an angle where at least one of the boats provided on the valve plate is separated from the bottom dead center by a desired angle. It is divided into a first boat and a second boat by providing a closed part that is approximately the same width as the port.

With this basic configuration, when the first boat and the second boat are connected to a pressure fluid source, the amount of movement of the piston in the cylinder block is approximately the length from the top dead center to the bottom dead center of the swash plate and the slope, and the first boat By connecting the first boat to the tank, the amount of movement of the piston is limited depending on the position of the first boat. In this way, the rotation speed can be changed by controlling the movement needle of the piston by simply changing the boat of the valve plate in the piston motor, so the outer shape of the piston motor is not changed in any way.

The present invention having the above basic configuration has the following unique effects.

Since the piston motor of the present invention can have the same external shape as a constant speed piston motor, it can be installed at the same mounting location as a constant speed piston motor. Therefore, conventionally, it was necessary to change the rotational speed of the motor by a combination of a constant speed piston motor and a transmission, but according to the present invention, a transmission is not required.

Furthermore, as disclosed in Japanese Patent Application Laid-Open No. 52-35304, two groups of cylinders separated in the radial direction are provided in the cylinder block, and W pressure fluid can be supplied to each of the two groups of cylinders to the valve plate. Although it is possible to solve the technical problem of the present invention by using a configuration in which a stone port is provided, this technique requires a special configuration for the cylinder block, and thus the configuration becomes multi-N. However, according to the present invention, a constant speed piston motor can be converted into a variable speed piston motor by simply changing the valve plate.

An embodiment of the present invention will be described below.

In Fig. 3, 1 is the main body. 2 is the rotation axis. Reference numeral 4 denotes a swash plate fixed to the main body 1, and has a slope 4a inclined at a predetermined angle with respect to the rotating shaft 2. Reference numeral 8 denotes a cylinder block, which has the same configuration as shown in FIG. -1 to 6-9 are passages 6-1' to 6-9 that open at the end surface 8a of the cylinder block 8 with the boat width W;
6-ff are in communication with each other, and pistons 5-1 to 5-9, which contact the slope 4a via shoes 12, are slidably fitted and connected to the rotating shaft 2 by a spline.

7 is a valve plate, which is fixed to the main body IK and is disposed between the end face 8a of the cylinder block 8 and the main body 1.
9a, 10. The first boat 21.10a is connected to each of the first boats 21.
21. '2nd baud) 22.22'.

As shown in tlE4 figure value), the first boat 21.21'
and the second boat 22, 22. The ends 21a and 22b of the first boat 21 and the second boat 22' are arranged symmetrically with respect to the center 0 (same as the center of rotation @2).
' and between the ends 2211) and 21a' of the second boat 22 and the first boat 21' are the bottom dead center al and the top dead center a.
The width of the boat is centered around the husbands of l′, and the width of K is approximately the same.
1, Wl' has a closed part Ht, H+', and between the ends 21b and 22a of the first boat 21 and the second boat 22 is a position a2 which is a predetermined angle α away from the bottom dead center al.
The port width wK is approximately equal to 1] W2's closed part H
2, and similarly a first boat 21' and a second boat 22
A closed portion H2/ having a width W 2 / equal to the boat width W is formed between the ends 21b' and 22a' of 22a', centered at a position a 2 / which is symmetrical with respect to the position a2 and the center 0. This is a configuration that has

The switching valve 23 is a switching valve for high/low speed switching, and is located at switching position 2 connecting the supply/discharge boats 9, 9a and 10.10a, respectively.
3a, and a switching position 23b for connecting each of the supply/discharge boats 9a, 10 and 9.10a. Moreover, the switching valve 24 is
Neutral position 24a connecting pressure fluid source 25 to tank 26
This configuration has a switching position 241 for forward rotation (in the direction of arrow B) and a switching position 240 for reverse rotation.

In the piston motor shown in this embodiment, the switching valve 2
4 to the switching position 24b and the switching valve 23 to the switching position 1823a
When operated respectively, the first boat 21' and the second boat 22 are connected to the pressure fluid source 25, and the first boat 21' and the second boat 22
' is connected to the tank 26. Therefore, pressure fluid is supplied to each cylinder 6-1 to 6-9 of the seven-cylinder block 8 until the center passes the bottom dead center a1 and reaches the top dead center ar' I/C. The fluid in the cylinders 6-1 to 6-9 flows out to the tank 26 until it passes the top dead center at' and reaches the bottom dead center alK. ．． a2
When ' is reached, the pressure fluid source 25 and the tank 26 are shut off by the closing parts Hl, H1', TH, H2'. For this reason, the movement of the pistons 5-1 to 5-6,
As shown in Figure 4 (1), bottom dead center a! to top dead center a +
/ Maximum 31 L 1 at the axis, and the rotational speed of the rotating shaft 2 becomes low.

Next, when only the switching valve 23 is switched to the switching position [23bK,
The second boat 22 and the first boat 21' are connected to a pressure fluid source 25
The second boat 22' and the first boat 21 are connected to the tank 26. Therefore, cylinders 6-1 to 6-9
until the center passes the position a2 and reaches the position a x /, it is connected with the pressure fluid source No. 25, and only when it reaches the position of the top dead center al', is it interrupted by the closing part H2 /. 17, until the centers of the cylinders 6-1 to 6-9 reach the position ax/ from the binary point al',
It is a pump action in which the pistons 5-1 to 6-9 are pressed by the slope 4a, and the second boat 22 and the first boat 21' are connected by the switching position 231), so that the first position a1' and the top dead end are connected. Point a symmetrical position a with respect to l/
2" and top dead center Bl', pressure fluid is supplied by the pump action. Therefore, the piston 5 during this period
The amount of movement from -1 to 5-9 does not act as a force to rotate the shaft 2 of one rotation. Therefore, the amount of movement of the pistons 5-1 to 5-9 is from position a2 to position a2 as shown in FIG.
"Until L"(L2<L), and the rotational speed of the rotating shaft 2 becomes high.

Next, another embodiment shown in FIGS. 5(a) and 5(g) will be described.

In the embodiment shown in FIG. 5(a)K, the switching valves 23 and 24 of the embodiment shown in FIG. 4(a) are combined into a switching valve 27. There are three switching positions: a neutral position 27a connected to the tank 26, a low speed switching position 27b for forward rotation (in the direction of arrow B), a medium speed switching position 27C, a high switching position 27d, and low speed, medium speed, and reverse rotation for reverse rotation. This configuration includes high-speed switching positions 27b's 27a/, 27eL'.

When the switching valve 27 is operated to the switching position 27bK, the first port 21. The second boat 22 is connected to a pressure fluid source, the first boat 2P is connected to a tank, and the second boat 22' is connected to a tank.
), the rotation speed of the shaft 2 becomes low for one rotation as Lt is from the bottom dead center al to the top dead center at'.

Next, when the switching position 27oK is operated, the second boat 22 is connected to the pressure fluid source 25, and the first boats 21, 21'
and the second boat 22' is connected to the tank 26, so
Piste 75-1 to 5-9 +Ml movement it is L from position a2 to top dead center a s / as shown in FIG.
B (L3<Ll), and the rotational speed of the rotating shaft 20 becomes faster by the amount of decrease in the amount of movement (Ll-Lm) than when operating to the switching position 1i1.27b. (Medium speed) Furthermore, when operated to switching position ff127cl, 1st baud) 21', 2nd baud) 2211-t, pressure fluid source 2
5 and connected to boat 21. Since the second boat 22' is connected to the tank 26, the movement τ of the pistons 5-1 to 5-9 is Lx (Lz<
L3<L1), and the rotational speed of the rotating shaft 2 becomes faster by the amount of decrease in the amount of movement (La-I, 2).

Note that the switching valves 24 and 27 in the fourth (a) and FIG.
27Q' and 27d', the rotation axis 2 only moves in the opposite direction to the arrow B, so a detailed explanation will be omitted.

[Brief explanation of the drawing]

Figure 1 is a sectional view of a conventional piston motor, and Figure 2 (a
2) is an enlarged view of the swash plate, the cross section of the cylinder block, and the pulp plate, and FIG. Second
Figure (C) is a diagram of the pulp plate seen in the direction of arrow A in Figure 2 (a). Fig. 3 is a sectional view of one embodiment of the present invention, the fourth part is a fluid circuit diagram of the connections of each boat of the pulp plate, and Fig. 4 (towards) shows the relative position of the slope and the pulp plate. Figure shown. FIG. 5(a) is a fluid circuit diagram of another embodiment of the connection relationship between the boats of the pulp plate, and FIG. 5(g) is a diagram showing the relative position between the slope and the pulp plate. 1... Main body 2... Rotating shaft 4... Swash plate 4a.
...Slope 5-1 to 5-9...Piston 6-1 to 6-
9... Cylinder 6-1' to 6-9'... Passage 7... Pulp plate 8... Cylinder block 9
s 9a, 10s 10a...- Supply/discharge boat 21.21
'...1st boat 22.22'...2nd boat)
w...Boat width wt, wl', W2.
W2'...Closed part al...Bottom dead center a1'
...Top dead center am, a2', a2"...Position Applicant: Japan Air Brake Co., Ltd.

Claims (1)

[Claims] (1) A swash plate having a slope inclined at a predetermined angle with respect to the rotation shaft, and a cylinder block in which a cylinder in which a plurality of pistons are slidably fitted is connected to the rotation shaft and comes into contact with the slope. , a valve plate disposed between the cylinder block and the main body and connected to the supply/discharge boat of the main body, a passage communicating with the cylinder is opened at the end face of the cylinder block with a predetermined port width, and a slope is provided on the valve plate. In a piston motor or pump provided with a boat having a closed portion having a width approximately equal to the width of the boat centered at the top dead center and the bottom dead center, at least one of the boats of the pulp plate is moved from the bottom dead center. , a piston motor or pump configured to have a closed portion having a width approximately equal to the width of a boat centered at a position separated by a desired angle.