JP2001248545A - Pneumatic driving hydraulic pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pneumatic driving hydraulic pump which can be fabricated inexpensively by mass production and module structuralization of a publicly known hydraulic pump. SOLUTION: The pump is provided with pilot valves 4, 5 in a stepped hole 12 of a valve bottom 3 and in a stepped hole 13 of a terminal cap 11 detachably disposed on a cylinder casing 2, and on the side of the valve bottom 3 with a switching control casing 25 incorporating a switching control piston 48 displaceable by an operating air AL. The switching control piston 48 displaces a sliding shoe 60. The operating air AL is introduced through the sliding shoe 60 into the operating chambers 34, 36 on both sides of an Air piston 6, and discharged air is transferred from the operating chambers 34, 36 to a peripheral outside air A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air piston which can be displaced in a plastic cylinder casing having an integrally formed valve bottom and which controls the switching of a pilot valve at both end positions, and a friction connection type air piston. The invention relates to a pneumatically driven hydraulic pump of the type comprising a hydraulic piston coupled to a hydraulic pump, the hydraulic piston being connected to a suction line via a suction valve and to a discharge line via a discharge valve.

[0002]

2. Description of the Related Art A pneumatically driven hydraulic pump of the type described above comprises
For example, it is known from DE 26 26 954 A1 and is awarded in the field on the basis of its various possibilities.

[0003] Such a hydraulic pump is, in a standard mode,
It has an air piston which can be reciprocated in a cylinder casing and a hydraulic piston which is frictionally connected to the air piston. The hydraulic piston is connected to the suction line via a suction valve and to the discharge line via a discharge valve. Due to the reciprocating movement of the pneumatic piston and thus of the hydraulic piston, the hydraulic piston first sucks in the hydraulic medium and then discharges the hydraulic medium under pressure.

[0004] The reciprocation of the air piston is effected via a partially hollow piston-type slide valve and at least one pilot valve, which is actuated by the pneumatic piston to move said piston-type slide valve one way. From the end position to the other end position. The piston slide valve has two differently sized working surfaces on the end face side. The smaller working surface is constantly loaded by the working air, whereas the larger working surface is loaded by the working air via the pilot valve when the piston slide valve is displaced in the other direction. . In order to transfer working air to the working chamber on both sides of the air piston and to bleed off the exhaust air, the piston type slide valve is provided in a stepped sleeve having a plurality of lateral holes and circumferential grooves which are expensive to manufacture. And a plurality of circumferential sealing lips guided at a distance from one another. A feature of the prior art is that, besides the complexity of the sleeve, the sealing ring constantly rubs through the opening of the bore in the sleeve and is therefore subject to significant wear. Furthermore, the sleeve must be supported in a sealed manner in the hydraulic casing bore in which it is received.

[0005]

The object of the present invention, starting from the prior art, is to make known hydraulic pumps cheaper to manufacture in terms of mass production and module construction. is there.

[0006]

Means for solving the above-mentioned problems of the present invention are as follows.
A first pilot valve is provided in a stepped bore formed in the valve bottom, and a second pilot valve is provided on a removable plastic end cap that closes the cylinder casing and guides the hydraulic piston. A switching control casing made of plastic is removably flanged to the side of the valve bottom, and two switching control casings are provided at both end sides in the switching control casing. A switching control piston having differently sized working surfaces can be reciprocated by working air while entraining a sliding shoe having a deflecting guide trough, so that, on one side, in the switching control casing. The working air which is always present in the room for guiding the sliding shoe in the valve bottom and the cylinder casing wall and end Via a passage formed in the cap, one or the other working chamber located on both sides of the air piston and alternately to the seals of the two pilot valves, and exhausted on the other side. Is connected to the surrounding air from the work chamber via a deflection guide trough in the sliding shoe.

[0007]

The remarkable features of the present invention are that a cylinder casing having an integrally formed valve bottom, a terminal cap detachably mounted on the cylinder casing, a switching control casing for a switching control piston, and a sliding shoe. Plastics, especially polyoxymethylene. These parts are advantageously formed as injection-molded parts. In this way, inexpensive mass production of products of all sizes and types is guaranteed.

It is further important that the sliding shoe is provided with the function of a flat slide valve. This sliding shoe can also be formed as a plastic injection molded product. The sliding shoe, depending on its position in the switching control casing, guarantees the introduction of working air into one or the other working chamber on both sides of the air piston, and has a deflection guide trough formed in the sliding shoe. Furthermore, based on
It makes it possible to transfer the exhaust air from the working room to the surrounding outside air, in particular via a silencer.

The displacement of the sliding shoe is effected by a switching control piston which is arranged in the switching control housing and has two differently sized working surfaces on both end faces. The smaller working surface is always located in the chamber of the switching control housing in which the sliding shoe is also located, and is permanently loaded with working air. The switching control piston can also be made from a light metal alloy and is hermetically guided in the switching control casing. However, the sealing member does not rub the opening of the hole, so there is no danger of particular wear. The sliding shoe is forcibly guided in the room, but slides along the outer surface of the valve bottom. The operating position of the sliding shoe is thus ensured by flange-fastening the switching control casing to the side of the valve bottom. The sliding shoe scrapes through all three passage openings. These passage openings are arranged one after the other in a row and extend in a transverse direction perpendicular to the direction of movement of the air piston. The two outer passages are connected directly to the working chamber in the cylinder housing, while the middle passage leads, in particular, to the surrounding air via a silencer.

According to a second aspect of the invention, the length section of the switching control piston which projects into the chamber of the switching control casing and has a smaller working surface on the end face side has the length of a rectangularly shaped sliding shoe. The frictional and mating connection between the switching control piston and the sliding shoe is particularly facilitated by the provision of a recess which extends over the sliding shoe and is adapted to the sliding shoe. Said recess is formed in particular by turning along the outer circumference of the switching control piston.

According to a third aspect of the present invention, the chamber of the switching control casing is always connected to a stepped hole for accommodating the first pilot valve through a perforated passage formed in the valve bottom. On the basis of this configuration, the larger working surface of the switching control piston is connected to the first pilot valve,
Whether to load with working air via the passage in the valve bottom and the passage in the switching control casing and to switch control the valve thrust of the second pilot valve into the working chamber between the air piston and the end cap. Alternatively, it is ensured, depending on the position of the air piston, that the thrust rod of the first pilot valve is pushed into the working space between the air piston and the valve bottom.

According to the fourth aspect of the present invention, the stepped hole formed in the valve bottom has a larger effect through a passage formed in the valve bottom and the switching control casing. It is connected to the space in the switching control casing which guides the length section of the switching control piston having a surface and is formed in said end cap via a passage formed in the wall of the cylinder casing and in the end cap. Connected to a stepped hole for accommodating the second pilot valve. The larger working surface is always located in the switching control housing space which is airtightly isolated from the chamber. This space can be supplied with working air via a first pilot valve provided in the valve bottom, and can be released into the surrounding outside air via a second pilot valve located in the end cap. is there. This further simplifies manufacture and assembly, since the switching control piston and the sliding shoe are not fixedly connected to one another.

To allow air to be drawn from said space, through a stepped hole with a second pilot valve, and also through a passage between the first pilot valve and said space and a second pilot valve. In addition, as described in claim 5, the stepped hole formed in the end cap is directly connected to the surrounding outside air through the lateral passage.

According to a sixth aspect of the present invention, there is provided a two-axis coaxial arrangement, wherein the two pistons are frictionally connected to the air piston.
One embodiment is provided with two hydraulic pistons. Second
In order to assemble the hydraulic piston, one appropriate guide hole may be provided in the valve bottom. No other changes are necessary for the double-acting hydraulic pump to work effectively.

As described in claim 7, the hydraulic pump of the present invention can be equipped with a manual operation mechanism. To this end, the pneumatic piston is manually operated via a connecting rod, which penetrates the valve bottom in a relatively movable manner, against the return force of a spring incorporated in the working chamber between said pneumatic piston and the end cap. It can be displaced. In short, it is only necessary to insert the spring into the cylinder casing and close the passage between the chamber and the working chamber adjacent to the end cap with a plug. No other changes are required. Thus, the hydraulic pump can be selectively operated pneumatically or manually.

According to the eighth aspect, the hand lever arranged corresponding to the connecting rod can be locked. With this configuration, it is possible to prevent a situation in which the hand lever performs an uncontrolled movement that may possibly cause damage when driving with air.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIGS. 1, 2 and 5 show a pneumatically driven hydraulic pump 1. The hydraulic pump 1 is displaceable in a plastic cylinder casing 2 having an integrally formed valve bottom 3 and controls an air piston 6 for switching between pilot valves 4 and 5 at both end positions. A hydraulic piston 7 frictionally connected to the hydraulic piston. The air piston 6 has a circumferential groove 8 in which a seal ring 9 is embedded.
It is in close contact with the inner wall 10 of the cylinder casing 2.

An end cap 11 made of plastic is detachably attached to the end of the cylinder casing 2 on the side opposite to the valve bottom 3. The end cap 11 is slidably connected through the hydraulic piston 7.

The pilot valves 4 and 5 are located in the stepped hole 12 of the valve bottom 3 and the stepped hole 13 of the end cap 11, respectively. Each pilot valve has a valve thrust rod 14 and a valve head 15. are doing. A seal ring 16 is arranged in a central length region of the valve thrust rod 14. Valve thrust 1
Another sealing ring 17 is located between 4 and the valve head 15. Pilot valves 4 and 5 are compression coil springs 18
And is supported by a screw bolt 19 screwed into the spring chamber 20 of the stepped holes 12, 13.

In the valve bottom 3, three lateral passages 21, 22, 23 which are arranged one after the other in a row are provided. A total of three lateral passages 21, 22, 23 are provided at the valve bottom 3
3 and 6, a switching control casing 25 made of plastic, which can be recognized in detail based on FIGS. 3 and 4, is flanged to the outer surface 24. As shown in FIG. Of the three lateral passages 21, 22, and 23, the central lateral passage 22 is connected to the end surface 26 of the valve bottom 3 through the passage 28.
Is connected to a connecting portion 27 which is open to the inside, and a muffler can be attached to the connecting portion. Of the remaining two lateral passages 21 and 23, the lateral passage 23 adjacent to the first pilot valve 4 is a vertical passage 30 formed in the wall 29 of the cylinder casing 2 and a passage 3 in the end cap 11.
It is connected via 1, 32, 33 to a working chamber 34 for the air piston 6 which is adjacent to the end cap 11. The third lateral passage 21 in the valve bottom 3 is connected via a passage 35 to a working chamber 36 adjacent to the valve bottom 3.

1 and 5, the length section 37 of the stepped hole 12 in the valve bottom 3, which guides the valve thrust rod 14, comprises the valve bottom 3, the wall 29 of the cylinder casing 2 and the terminal end. Passages 39, 4 formed in cap 11
It is connected to the spring chamber 20 of the stepped hole 13 in the end cap 11 via 0, 41, 42. Further, the passage 39
Is connected to a space 45 in the switching control casing 25 via another passage 43 in the valve bottom 3 and a passage 44 in the switching control casing 25, in which a switching control piston described in detail below is connected. 48, seal ring 4
The length section 47 with 6 is displaceable.

A length section 38 located between the length section 37 of the stepped hole 13 in the end cap 11 and the spring chamber 20.
Are connected to the ambient outside air A via the lateral passage 49.

The switching control piston 48 is hermetically guided in the space 45 on one side of the switching control casing 25 and in a hole 50 on the other side. For this purpose, another sealing ring 51 is embedded in the circumferential groove 52 of the switching control piston 48. A length section 54 of the switching control piston 48 having a recess 53 formed by turning protrudes into a chamber 55 of the switching control casing 25. This chamber 55 is connected to the working air AL via a connection 56.
(Pressure air) is always in communication with the pneumatic source. The end 57 of the switching control piston 48 located in the chamber 55 has a working surface 58 on the end face side, which is the working surface of the length section 47 of the switching control piston 48 located in the space 45. Less than 59.

The recess 5 provided on the switching control piston 48
The length of 3 corresponds to the length of a plastic sliding shoe 60 formed in a rectangular shape, and a deflection guide trough 61 is formed in the sliding shoe. This sliding shoe 60
Slides along the outer surface 24 of the valve bottom 3 and rubs the openings of the three lateral passages 21, 22, 23.

As can be seen from FIGS. 1, 4, 5 and 7, the chamber 55 is connected to the spring chamber 20 of the stepped hole 12 formed in the valve bottom 3 through the perforated passage 62. .

The hydraulic piston 7 operates in the T-shaped passage 63 of the high-pressure casing 65. The T-shaped passage is connected on one side to a suction line 66 for hydraulic medium via a suction valve 64.
And on the other side to a discharge conduit 68 via a discharge valve 67.

The operation of the hydraulic pump 1 shown in FIGS. 1 to 7 is as follows. That is, based on the configuration of the switching control casing 25, the working air AL always stays in the chamber 55 via the connection portion 56. As a result, the switching control piston 48 is displaced toward the left hand when viewed in the drawing plane (FIGS. 3 and 4), and furthermore, the friction control connection and the form-fit connection of the switching control piston 48 and the sliding shoe 60 provide The sliding shoe is entrained until it comes into contact with the end face 69 of the chamber 55. Thus, the working air AL flows from the chamber 55 into the horizontal passage 23, the vertical passage 30, and the passages 31, 32, 33.
Through the working chamber 34 adjacent to the end cap 11
Reach inside. In this position of the sliding shoe 60, the working chamber 36 adjacent to the valve bottom 3 has the passage 35, the lateral passage 2
1. Deflection guide trough 61 in sliding shoe 60, lateral passage 2
The air piston 6 can move toward the valve bottom 3 due to its connection to the ambient outside air A via 2 and the passage 28. At the same time, the working air AL is loaded from the chamber 55 via a perforated passage 62 formed in the spring chamber 20 of the first pilot valve 4, whereby the valve thrust rod 14 of the first pilot valve 4 is moved in FIG. Displaced into the working chamber 36 as shown.

Immediately before reaching the top dead center, the air piston 6
The valve thrust rod 14 of the first pilot valve 4 is operated, and the valve thrust rod is displaced against the return force of the compression coil spring 18 to separate the seal ring 17 from the seal seat of the stepped hole 12. The working air AL thus supplied into the perforated passage 62 flows into the passage 39 via the length section 38 of the stepped hole 12 and passes through the passage 43 in the valve bottom 3 and the switching control casing 25. Through the passage 44 of
It reaches into the space 45 guiding the length section 47 with the larger working surface 59. At the same time, the working air AL
The passages 40, 41, in the spring chamber 20 of the second pilot valve 5
The pressure is supplied via 42. The thrust rod 14 of this second pilot valve is thereby displaced into the working chamber 34 adjacent to the end cap 11.

Due to the fact that the working surface 59 of the switching control piston 48 located in the space 45 is larger than the working surface 58 of the switching control piston 48 located in the chamber 55, the switching control piston 48 slides. With the shoe 60, the ring surface 70 of the switching control piston 48 is moved toward the connection portion 56 for the working air AL until the ring surface 70 of the switching control piston 48 comes into contact with the ring surface 71 of the switching control casing 25 (FIGS. 6 and 7). . Due to the displacement of the switching control piston, the communication between the connecting part 56 and the working chamber 34 adjacent to the end cap 11 is interrupted, and instead, the working chamber 34 is connected to the end cap 11 and the cylinder casing 2. Passages 31, 3 formed in wall 29 and valve bottom 3
2, 33, the vertical passages 30, 72, and the lateral passage 23 are connected to the deflection guide trough 61 in the sliding shoe 60, and then to the ambient air A through the lateral passage 22 in the valve bottom 3 and the passage 28. Is done.

The working air AL now reaches the working chamber 36 adjacent to the valve bottom 3 via the lateral passage 21 and the passage 35 in the valve bottom 3, and places the air piston 6 in the end cap 11.
Displace toward.

When the thrust rod 14 of the first pilot valve 4 loses contact with the air piston 6, the thrust rod 1
4 is displaced by the compression coil spring 18 to the position shown in FIG. The seal ring 17 is pressed against a seal seat in the stepped hole 12. The communication between the perforated passage 62 and the passage 39 connecting to the length section 38 of the stepped bore 12 in the valve bottom 3 is interrupted. This allows air to flow through the passages 39,
40, 41, 42, 43 and the space 45 as well as in the spring chamber 20 of the second pilot valve 5.

The air piston 6 contacts the valve thrust rod 14 of the second pilot valve 5 just before reaching the bottom dead center and separates the seal ring 17 of the valve thrust rod from its seal seat, so that it is contained. The ambient air is now passed through the spring chamber 20 of the second pilot valve 5, the length section 38 of the stepped hole 37, and the lateral passage 49 in the end cap 11.
Can be relieved.

Therefore, since the space 45 in the switching control casing 25 is connected to the ambient outside air A, the working air AL displaces the switching control piston 48 and, consequently, the sliding shoe 60 toward the space 45 again. Thus, the next work cycle is started anew. Air piston 6
Piston 7 based on the transmission ratio between
Draws hydraulic medium from suction line 66 via suction valve 64 in one direction of movement, and then discharges hydraulic medium under high pressure through discharge valve 67 in the other direction of movement.
8. Due to the reciprocating oscillating movement of the air piston 6 and thus of the hydraulic piston 7, a substantially pulsating pressure-free flow is generated in the discharge conduit 68.

FIG. 8 schematically shows an embodiment of a pneumatically driven hydraulic pump 1a, which is in principle described above with reference to FIGS. Equivalent to the embodiment. However, another hydraulic piston 7a is coaxially arranged on the hydraulic piston 7. This further hydraulic piston 7a is also connected to the pneumatic piston 6 in an arrowhead frictional connection and penetrates the valve bottom 3 of the cylinder housing 2 in a sliding connection. Another hydraulic piston 7a, like the first hydraulic piston 7, also works in the T-shaped passage 63 of the high-pressure casing 65, and furthermore, the suction valve 64
Through the suction conduit 66 and then through a discharge valve 67 under high pressure to discharge and transfer to the conduit 68.

As described above, the embodiment shown in FIG. 8 is otherwise the same as the embodiment shown in FIGS. 1 to 7, and a duplicate description of this structure will be omitted here.

The embodiment of the hydraulic pump 1b schematically shown in FIGS. 9 and 10 also has in principle the structure of the hydraulic pump 1 shown in FIGS.

However, a manual actuation mechanism is additionally superimposed on this structure. The air piston 6 is connected via a connecting rod 73 that penetrates the valve bottom 3 so as to be able to move relatively.
Work chamber 34 between air piston 6 and end cap 11
It can be manually displaced against the return force of the compression coil spring 74 incorporated therein. For this purpose, the chamber 55 in the switching control casing 25 and the longitudinal passage 30 leading to the working chamber 34 between the end cap 11 and the air piston 6
And the passages 31, 32, 33 are closed.

The connecting rod 73 has a hand lever 75. By pivoting the hand levers 75 around the longitudinal axis 76 of the hydraulic pump 1b by 180 °, the connecting rod 73 is reciprocated within the cylinder casing 2 by the stroke of the air piston 6; Via a hydraulic piston 7 frictionally connected to the piston 6, the hydraulic medium is sucked from a suction line 66 via a shunt valve 64 and discharged into a discharge line 68 via a discharge valve 67. You.

When the hydraulic pump of the embodiment shown in FIGS. 9 and 10 is to be operated by pneumatic pressure, the hand lever 75 is locked at a position recognizable from FIG. The vertical passage 30 and the passages 31, 32, 33 are always closed by the plug 77. The suction stroke is always performed by the spring 74.

The lower piston chamber 34 is sucked in through a passage 78. A suitable filter element 79 pressed into the intake hole prevents contamination of said lower piston chamber 34.

When the pneumatic operation is resumed, the hand lever 75
Is stationary and does not cause damage.

[Brief description of the drawings]

FIG. 1 is a schematic vertical longitudinal sectional view of a pneumatically driven hydraulic pump.

FIG. 2 is a side view of the hydraulic pump as viewed in the direction of arrow II in FIG.

FIG. 3 is a horizontal cross-sectional view taken along the line III-III of FIG. 2;

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3;

FIG. 5 is a vertical vertical sectional view corresponding to FIG. 1 shown in another operation state.

FIG. 6 is a horizontal cross-sectional view corresponding to FIG. 3 in another operation state.

FIG. 7 is a cross-sectional view corresponding to FIG. 4 in another operation state.

FIG. 8 is a vertical vertical sectional view of a pneumatically driven hydraulic pump according to another embodiment, corresponding to FIG. 1;

FIG. 9 is a vertical vertical sectional view corresponding to FIG. 5 of a pneumatically driven hydraulic pump according to another embodiment.

10 is a vertical vertical sectional view of the pneumatically driven hydraulic pump shown in another operating position, corresponding to FIG. 9;

[Explanation of symbols]

1, 1a, 1b hydraulic pump, 2 cylinder casing, 3 valve bottom, 4 first pilot valve, 5 second pilot valve, 6 air piston, 7, 7a hydraulic piston, 8 circumferential groove, 9
Seal ring, 10 inner wall, 11 end cap, 12, 13 stepped hole, 14 valve thrust rod, 15 valve head, 16, 17 seal ring, 18 compression coil spring, 19 screw bolt, 20 spring chamber, 21, 22, 23 Lateral passage, 24 outer surface, 25 switching control casing, 26 end face, 27 connection, 28 passage, 29 wall, 30 vertical passage, 31, 32,
33 passage, 34 working chamber adjacent to end cap, 35 passage, 36 working chamber adjacent to valve bottom, 37, 38 length section of stepped hole,
39, 40, 41, 42, 43, 44 passage, 45
Space, 46 seal ring, 47 length section, 48 switching control piston, 49 side passage, 50 hole, 51 seal ring, 52
Circumferential groove, 53 recessed part, 54 length division, 5
5 chamber, 56 connection, 57 end of switching control piston, 58, 59 working surface of switching control piston, 60 sliding shoe, 61 deflection guide trough, 62 drilling passage, 63 T-shaped passage, 64
Suction valve, 65 high pressure casing, 66 suction conduit, 67 discharge valve, 68 discharge conduit,
69 end face, 72 vertical passage, 73 connecting rod, 74 spring, 75 hand lever, 76
Vertical axis, 77 plug, 78 passage, 79 filter element, A ambient outside air, AL working air

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H075 AA01 BB03 BB12 BB15 BB16 BB17 CC03 CC08 CC18 CC28 CC30 CC32 CC33 CC35 CC36 DA02 DA04 DA09 DA21 DA30 DB10 DB13 DB42 DB43 DB44 DB45 DB46 DB48 DB50 EE12 EE18 3H081 AA03 BB03 CC HH10

Claims (8)

[Claims] 1. An air piston (6) displaceable in a plastic cylinder casing (2) having a valve bottom (3) formed integrally therewith and switchingly controlling a pilot valve (4, 5) at both end positions; , The air piston (6)
A hydraulic piston (7) frictionally connected to the
A pneumatically driven hydraulic pump, wherein the hydraulic piston is connected to a suction conduit (66) via a suction valve (64) and to a discharge conduit (68) via a discharge valve (67). In (1, 1a, 1b), the first pilot valve (4) has a stepped hole (1) formed in the valve bottom (3).
2) and a second pilot valve (5)
The valve casing is provided in a stepped hole (13) formed in a detachable plastic end cap (11) for closing the cylinder casing (2) and guiding the hydraulic piston (7). A switching control casing (25) made of plastic is detachably flanged to the side of (3), and in the switching control casing, two differently sized working surfaces (58,
59) with one switching control piston (48)
The working air (AL) can reciprocate while entraining a sliding shoe (60) having a deflection guide trough (61), so that on one side the sliding shoe (25) in the switching control casing (25). Working air (AL) constantly present in the chamber (55) guiding the (60) is formed in the valve bottom (3) and the wall (29) and the end cap (11) of the cylinder casing (2). Through the passages (21, 22, 23, 30, 31, 32, 33) into one or the other working chambers (36, 34) located on both sides of the air piston (6), The pressure is alternately supplied to the seals (16, 17) of the pilot valves (4, 5), and exhaust gas is exhausted on the other side to the working chamber (3, 5).
Pneumatically driven hydraulic pump, characterized in that it is connected to the ambient air (A) via a deflection guide trough (61) in the sliding shoe (60). 2. A chamber (5) of a switching control casing (25).
5) The smaller working surface (58) that protrudes into the end face side
Length section (5) of the switching control piston (48) having
4. The device according to claim 1, wherein 4) has a perimeter recess (53) adapted to the length of the sliding shoe (60) formed in a rectangular shape and covering the sliding shoe (60). Hydraulic pump. 3. A chamber (55) is constantly connected to a stepped hole (12) for receiving a first pilot valve (4) through a perforated passage (62) formed in a valve bottom (3). The hydraulic pump according to claim 1, wherein the hydraulic pump is provided. 4. A stepped hole (12) formed in a valve bottom (3) is formed with a passage (39, 43, 4) formed in said valve bottom (3) and in a switching control casing (25).
4) is connected via a space (45) in a switching control housing (25) which guides a length section (47) of a switching control piston (48) having a larger working surface (59) and A second pilot formed in said end cap (11) via a passage (40, 41, 42) formed in the wall (29) of the cylinder casing (2) and in the end cap (11). 4. The hydraulic pump according to claim 1, wherein the hydraulic pump is connected to a stepped hole (13) for receiving the valve (5). 5. The method as claimed in claim 1, wherein the stepped hole (13) formed in the end cap (11) is connected to the ambient outside air (A) via a lateral passage (49). The hydraulic pump according to claim 1. 6. A pneumatic piston (6) passes coaxially with the hydraulic piston (7) through the valve bottom (3) for relative movement and on one side via a suction valve (64). In the suction conduit (66) and on the other side the discharge valve (6)
6. Hydraulic pump according to claim 1, wherein the hydraulic pump is frictionally connected to a second hydraulic piston (7a) connected to the discharge line (68) via (7). . 7. The air piston (6) is provided with a valve bottom (3).
The air piston (6) and the end cap (1) are connected via one connecting rod (73) penetrating the air piston relative to the air piston.
1) and a spring (7) incorporated in the working chamber (34).
A communication path between the working chamber (34) and the chamber (55) which is manually displaceable against the returning force of 4) and is interposed between the end cap (11) and the air piston (6). 6. The hydraulic pump according to claim 1, wherein the hydraulic pump is closed. 8. The hydraulic pump according to claim 7, wherein a hand lever (75) arranged corresponding to the connecting rod (73) is lockable.