JPH0640941Y2 - Variable capacity oblique shaft type hydraulic rotary machine - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to improvement of a variable displacement type oblique shaft type hydraulic rotary machine as a hydraulic pump and hydraulic motor used in civil engineering / construction machinery and other general machines.

[Conventional technology]

FIG. 4 shows a hydraulic pump as an oblique shaft type hydraulic rotary machine according to the prior art.

In the figure, 1 is a casing composed of a substantially cylindrical casing body 1A and a head casing 1B that closes one end of the casing body 1A, and 2 is a rotatably projecting projection in the casing body 1A. A rotary shaft 4 rotatably supported via a cylinder block is located inside the casing body 1A and rotates together with the rotary shaft 2. A plurality of cylinders 5 are bored in the cylinder block 4 in the axial direction. It is set up. A piston 6 is reciprocally provided in each cylinder 5, and a connecting rod 7 is attached to each piston 6. A spherical portion 7A is formed at the tip of each connecting rod 7, and the spherical portion 7A is a drive disk 2A formed at the tip of the rotary shaft 2.
It is swingably supported by.

Reference numeral 8 denotes a valve plate. One end face of the valve plate 8 is in sliding contact with the cylinder block 4, and the other end face thereof is a concave arc shape centered on a tilt center O ₁ described later formed on the head casing 1B. Slidably slidably contacting the tilt sliding surface 9 of
A through hole 8A is formed at the center of the valve plate 8 into which the tip ends of a center shaft 10 and a swing pin 15 described later are inserted from both sides.
Has been drilled. The valve plate 8 is provided with a supply / discharge port (not shown) that intermittently communicates with each cylinder 5 by the rotation of the cylinder block 4, and the supply / discharge port is a tilted position of the valve plate 8. Head casing regardless of
It is adapted to communicate with a supply / discharge passage (not shown) that opens to the tilt sliding surface 9 of 1B.

Reference numeral 10 is a center shaft for supporting the cylinder block 4 between the drive disc 2A and the valve plate 8. The center shaft 10 has a spherical portion 10A formed at one end thereof, and the spherical portion 10A is formed on the drive disc 2A. It is swingably supported around O ₁ as the tilt center. On the other hand, the other end of the center shaft 10 protruding through the center of the cylinder block 4 is slidably inserted into the through hole 8A of the valve plate 8 to perform centering between the cylinder block 4 and the valve plate 8. Has been.

Reference numeral 11 is a tilting mechanism for tilting the valve plate 8 along the tilting sliding surface 9, and the tilting mechanism 11 is provided in the head casing 1B and has oil passage holes 12A, 12B at both axial ends. The chamber 12 and the cylinder chamber 12 are slidably inserted into the chamber 12.
Servo piston 14 defining axially opposite sides in hydraulic chambers 13A, 13B, and a peripheral body portion of servo piston 14 inserted in a direction orthogonal to the axis thereof, and spherical tip portion 15A is formed in through hole 8A of valve plate 8.
And a rocking pin 15 that is rockably inserted into the hydraulic pressure chambers 13A and 13B so that the valve plate 8 and the cylinder block 4 can be integrally tilted by supplying and discharging pressure oil to and from the hydraulic chambers 13A and 13B. Has become.

The hydraulic rotary machine according to the prior art has the above-mentioned configuration. Next, the operation of the hydraulic rotary machine used as a hydraulic pump will be described.

First, the tilting mechanism 11 tilts the valve plate 8 together with the cylinder block 4 to the tilting position shown. Therefore, for example, pressure oil from an auxiliary pump for tilt control is supplied to the hydraulic chamber 13A (13B) on one side of the cylinder chamber 12 to displace the servo piston 14. Then, together with the servo piston 14, a swing pin 15
Is also displaced, and the valve plate 8 is tilted while sliding on the tilt sliding surface 9, so that the cylinder block 4 is also tilted, and its rotation center axis is tilted with respect to the rotation center axis of the rotation shaft 2. Tilt to the maximum rolling side (minimum tilting side), and the state shown in the drawing is obtained.

Next, the drive source such as the engine and the electric motor is rotated to rotate the rotary shaft 2
When the rotary drive is performed, each piston 6 inserted in the drive disk 2A of the rotary shaft 2 and the cylinder 5 of the cylinder block 4 is rotated.
The cylinder block 4 is rotated together with the rotating shaft 2 because the connecting rod 7 is connected to the cylinder block 4. Then, each piston 6 reciprocates in the cylinder 4 while the cylinder block 4 is rotating. When each piston 6 retreats from the inside of the cylinder 5, it becomes an intake stroke in which hydraulic oil is sucked into the cylinder 5 from the supply / discharge passage through the supply / discharge port. When the piston 6 enters the cylinder 5, 5 is a discharge stroke in which the hydraulic oil in 5 is pressurized and discharged from the supply / discharge passage through the supply / discharge port.

[Problems to be solved by the device]

However, in the conventional technology configured as described above, the head casing 1B is provided with the cylinder chamber 12 which is elongated in the upper and lower direction, and the servo which constitutes the tilting mechanism 11 is formed in the cylinder chamber 12. A piston 14 is slidably provided. Moreover, the head casing 1B is provided with a pressure regulator (not shown) that detects the load of the pump to supply and discharge the control pressure in the cylinder chamber 12 to prevent pump overload, and is used as a hydraulic motor. In this case, an overload relief valve, a counter balance valve, etc. (none of which are shown) are provided.

As described above, in the sector type oblique shaft type hydraulic rotating machine according to the prior art, the servo piston 14 is disposed in the head casing 1B outside the sliding radius of the valve plate 8, and the pressure regulator, It has a structure in which control devices such as an overload relief valve and a counterbalance valve are provided. Therefore, the head casing 1B becomes longer in the operating direction of the servo piston 14 and comes out of the casing body 1A.

For this reason, when the hydraulic rotary machine is applied as a hydraulic pump or hydraulic motor for construction machinery and is used in winter or in cold regions, the casing 1 made of a metal material, particularly the head casing 1B, is exposed to cold air and becomes cold. It is in an easy state. As a result, the control pressure oil that operates the servo piston, the pressure regulator, and other control devices is likely to cool and become low temperature, and the viscosity also increases. Thus, there is a problem that the operation as a construction machine becomes slow due to the response delay of the tilting mechanism and the control device. Also, the temperature rise is slow even during warm-up operation and load operation,
The response delay of the control device becomes a problem.

The present invention has been made in view of the above-mentioned problems of the prior art, and the pressure oil supplied to and discharged from the cylinder block through the supply / discharge passage and the valve plate is used to warm the vicinity of the servo piston, thereby making It is an object of the present invention to provide a variable displacement oblique shaft type hydraulic rotating machine capable of stably operating a rolling mechanism, a control device and the like.

[Means for Solving the Problems]

To achieve the above object, the present invention provides a cylindrical casing having a head casing, a rotating shaft rotatably supported in the casing, and a rotating shaft provided in the casing and rotating with the rotating shaft. A cylinder block, a piston reciprocally provided on the cylinder block, and one end side of which is oscillatably supported by the rotary shaft, one end surface of the cylinder block slidably contacts the other end surface of the head casing. In a variable displacement oblique shaft type hydraulic rotating machine comprising a valve plate slidably abutting on a tilt sliding surface and a tilt mechanism for tilting the valve plate together with the cylinder block, the tilt mechanism comprises: A servo piston disposed on the minimum tilting side of the valve plate and disposed on the peripheral wall portion of the head casing; and a link mechanism connecting the servo piston and the valve plate, and The head casing is provided with a pair of supply / discharge passages located on both sides of the servo piston so as to sandwich the servo piston and extending in the same direction as the servo piston. It is characterized in that the valve plate is opened to the minimum tilt side.

[Action]

By arranging the servo piston in the direction orthogonal to the rotation axis in this way, the linear motion of the servo piston is directly transmitted to the valve plate through the link mechanism, and the circular arc motion of the valve plate is smoothly performed. Can be done. At this time, since the head casing is provided with a pair of supply / discharge passages located on both sides of the servo piston so as to sandwich the servo piston and extending in the same direction, even when used in a winter cold region, The vicinity of the servo piston of the head casing is warmed by the pressure oil flowing through the supply / discharge passage, and the delay of the machine operation due to the response delay of the tilting mechanism can be prevented.

〔Example〕

Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 3. The same components as those of the above-described conventional technique are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, 21 is a casing according to the present embodiment, the casing 21 is a cylindrical casing body 22 as in the case of the prior art, and a covered cylindrical head casing 23 for closing the head side of the casing body 22. It consists of
Since the tilting mechanism 25, which will be described later, is provided on the peripheral wall portion of the head casing 23, the axial dimension of the casing 21 is shorter than that of the conventional head casing 1. Here, the casing body 22 is formed of a cylindrical portion 22A that supports the rotating shaft 2 via the bearing 3 and a flange portion 22B that abuts against the head casing 23. Further, the head casing 23 has a substantially rectangular tube portion 23A and a flange portion 23B that abuts the flange portion 22B of the casing body 22.
A lid portion 23C that covers the tubular portion 23A, a cylinder forming portion 23D that is located near the lid portion 23C, and is provided so as to project upward on the upper peripheral wall portion of the tubular portion 23A, and the cylinder forming portion. 23D is sandwiched from the left and right sides, and is integrally formed with a supply / discharge passage forming portion 23E that is bulged in the lid portion 23C. The upper ends of the forming portions 23E and 23F are external pipe mounting flanges 23E ₁ and 23F ₁ .

Reference numeral 24 denotes a valve plate used in this embodiment. Like the valve plate 8 of the prior art, the valve plate 24 has one end surface slidingly contacting the cylinder block 4 and the other end surface tilting and sliding of the head casing 23. A supply / discharge port 24B, 24C which is slidably in contact with the surface 9, has a bottomed insertion hole 24A formed in the center of the valve plate 24 and into which the tip end of the center shaft 10 is inserted, and communicates with each cylinder 5 intermittently. Has been formed. However, the valve plate 24 of the present embodiment is formed with bearing holes 24D, 24D (however, one is not shown) into which the connecting pin 31 described later is inserted in the center in the thickness direction and the height direction on both end faces thereof. The difference is that (see Fig. 3).

Reference numeral 25 is a tilting mechanism of this embodiment provided in the head casing 23. The tilting mechanism 25 is the minimum tilting side of the valve plate 24 (upper side in FIG. 1) and is substantially the same as the valve plate 24. A cylinder chamber 26 with a lid, which is located on the plane H-H and is formed in the cylinder forming portion 23D in a direction orthogonal to the axis A-A of the rotary shaft 2, and is slidably inserted into the cylinder chamber 26. A servo piston 27 formed of a piston rod portion 27B extending into the head casing 23 through the piston portion 27A and the cylindrical portion 23A, and a cylinder defined by the servo piston 27 for operating the servo piston 27. Oil passage holes 28A and 28B for communicating the upper and lower chambers with the hydraulic source and the tank, and the pin 29 on one end side
A link 30 which is rotatably connected to the tip of a piston rod portion 27B of the servo piston 27 via a link and is branched into a semicircular bifurcated portion so that the other end side straddles the valve plate 24;
Bearing holes 24D of the valve plate 24
The connecting pins 31 and 31 are rotatably inserted into the connecting pin 31, and the pin 29, the link 30 connecting pin 31 and the like constitute the link mechanism of this embodiment. A shuttle valve 32 provided between supply and discharge passages 33 and 34, which will be described later, is used as a hydraulic pressure source for the oil passages 28A and 28B, and high-pressure oil derived from the shuttle valve 32 is used as a directional switching valve (Fig. Through the oil passage hole 28A,
Servo piston 27 by selectively supplying to 28B
Is designed to operate.

Thus, the servo piston 27 is arranged on the peripheral wall portion of the head casing 23 so as to be positioned on the minimum tilting side of the valve plate 24 and to form a plane H-H substantially the same as the valve plate 24, and the oil passage holes 28A, 28B.
By supplying and discharging the pressure oil for tilt control from the servo piston 27, the servo piston 27 is slidably displaced in a direction substantially orthogonal to the axis AA of the rotary shaft 3, and the valve plate 24 and the cylinder block 4 are connected via the link 30. The tilt is controlled integrally.

Further, 33 and 34 denote a pair of supply / discharge passages arranged so as to extend in the same direction as the servo piston 27 in order to supply / discharge pressure oil as a hydraulic rotary machine. , 3
4 are respectively formed in the supply / discharge passage forming portions 23E, 23F of the head casing 23, the inlets 33A, 34A thereof are opened to the external pipe mounting flanges 23E ₁ , 23F ₁ , and the supply / discharge ports 33B, 34B are "L". It is bent in a letter shape and opens at the supply / discharge ports 24B, 24C of the valve plate 24, respectively.

In the figure, 35 and 36 are overload relief valves provided in the head casing 23.

The present embodiment is configured in this way, and its operation will be described next.

First, in order to tilt the valve plate 24 together with the cylinder block 4 by the tilting mechanism 25, pressure oil is supplied to the cylinder chamber 26 from the oil holes 28A (28B), and the servo piston 27 is displaced as a linear motion. As a result, the valve body 24 slides on the tilt slide surface 9 via the link 30 and the connecting pin 31 connected to the piston rod portion 27B of the servo piston 27, and as a result, the cylinder block 4 also moves. Tilting, and its rotation center axis is the tilt maximum side (tilt minimum side) with respect to the axis AA of the rotary shaft 2.
And the state shown in FIG. 1 is obtained.

At this time, while the servo piston 27 moves linearly,
Although the valve plate 24 is guided by the tilting sliding surface 9 and moves in an arc, the servo piston 27 and the link 30 are rotatably connected via a pin 29, and the link 30 and the valve plate 24 are connected by a connecting pin 31. Since it is rotatably connected via, it is possible to smoothly convert the linear motion and the arc motion.

Next, in order to operate as a hydraulic pump with the cylinder block 4 tilted together with the valve plate 24 as described above,
As in the prior art, the cylinder block 4 is rotated together with the rotary shaft 2 to reciprocate the piston 6 in the cylinder 5.
As a result, in the intake stroke, the valve plate is passed through the intake / exhaust passage 33 (34).
The hydraulic oil is sucked from the 24 supply / discharge ports 24B (24C), and the pressure oil is discharged to the outside from the supply / discharge port 24C (24B) through the supply / discharge passage 34 (33) in the discharge process.

Thus, according to the present embodiment, the cylinder chamber 26 forming the tilting mechanism 25 is a cylinder 23A of the head casing 23, which is a peripheral wall part, is close to the lid part 23C, and is formed on the tilting minimum side. The servo piston 2 is provided in the cylinder chamber 26 in the forming portion 23D.
7 is slidably provided, while the lid portion 23C of the head casing 23 is provided.
Is provided with supply / discharge passage forming portions 23E, 23F so as to sandwich the servo piston 27 from the left and right, and the supply / discharge passage forming portions 23E, 23F are provided with the supply / discharge passage 33 in the same direction as the sliding direction of the servo piston 27. , 34
Is provided.

As a result, the pressure oil heated to a high temperature is supplied to the supply / discharge passages 33, 34 by the pump action of the hydraulic rotary machine,
From the supply / discharge passage forming portions 23E, 23F of the head casing 23 to the vicinity of the cylinder forming portion 23D, it is warmed by the pressure oil. Even when the hydraulic rotating machine operates as a motor, the pressurized oil having a high temperature flows through the supply / discharge passages 33, 34, so that the vicinity of the cylinder forming portion 23D is quickly warmed, so that the hydraulic rotating machine Warm-up time can be shortened.

Thus, even when the hydraulic rotary machine is used as a construction machine pump or motor in winter or in cold regions, it is possible to solve the problem that the servo piston 27 of the tilting mechanism 25 projects because of the protrusion. Therefore, the operation delay of the entire construction machine due to the response delay of the servo piston 27 due to the cooling of the control pressure oil that operates the tilting mechanism 25 and the increase in viscosity can be eliminated. Further, even during the warm-up operation or immediately after the start-up, the temperature rise in the vicinity of the tilting mechanism 25 is accelerated or the heating state is maintained, so that the operation delay can be eliminated. Further, in addition to the tilting mechanism 25, overload relief valves 35 and 36, counter balance valves, pressure regulators, and the like can similarly eliminate the operation delay.

On the other hand, the linear motion of the servo piston 27 can be immediately transmitted as an arc motion of the valve plate 24 via the link 30, and the load acting on the servo piston can be made almost zero. Can be slid smoothly in the cylinder chamber 26.

Further, since the tilting mechanism 25 is provided on the peripheral wall portion of the head casing 23, as compared with a tilting mechanism 11 provided on the axial end surface of the head casing 1B like the tilting mechanism 11 according to the related art,
The axial dimension of the entire casing 21 can be shortened.

Further, the pin 29, the link 30, the connecting pin 31, etc., which constitute the link mechanism, can be provided in the cylinder block tilting space in the casing 21, which is originally a dead space, so that the dead space can be effectively used and the casing can be effectively used. It is possible to reduce the weight of 21 and make it compact.

It should be noted that the present invention uses the servo piston 27 for the head casing 23.
It is sufficient to provide it on the peripheral wall portion located on the minimum tilting side and to provide a pair of supply / discharge passages 33, 34 so as to sandwich the servo piston 27. As in the embodiment, it is substantially flush with the valve plate 24. Even if the servo piston 27 is slightly tilted so as to be orthogonal to the axis of the cylinder block 4 in a state where the cylinder block 4 and the valve plate 24 are tilted toward the minimum tilt side without having to be positioned above. Good.

Further, the link mechanism is not limited to the configuration of the embodiment, and other configurations may be used as long as they can convert the linear movement of the servo piston 27 into the circular movement of the valve plate 24.

Further, since the servo piston 27 only needs to be operated by the control pressure for tilting, the servo piston 27 is not limited to the one using the pressure oil from the shuttle valve 32 as its own pressure, but may be one operated by the external pilot pressure.

[Effect of device]

The variable displacement oblique shaft type hydraulic rotating machine according to the present invention is as described above in detail, and the tilting mechanism is located on the minimum tilting side of the valve plate and is disposed on the peripheral wall of the head casing. A pair of feeds that are composed of a piston and a link mechanism that connects the servo piston and the valve plate, and are located on both sides of the servo piston in the head casing so as to sandwich the servo piston and extend in the same direction. Since the exhaust passage is provided, the effects of the following items are achieved.

Since the vicinity of the servo piston is warmed by the pressure oil flowing through the supply / discharge passages provided on both sides of the servo piston, it is possible to prevent the tilting mechanism from being delayed in operation even when it is used in winter or in cold regions.

Since the servo piston is provided on the peripheral wall portion of the head casing and on the minimum tilt side of the valve plate, moment load is not applied to the servo piston, and stable tilting operation can be performed.

Since the servo piston can be arranged on the peripheral wall portion of the head casing, the axial dimension of the entire casing can be shortened.

Since the servo piston and the supply / discharge passage are provided in the same direction, it is possible to combine the machining of the cylinder hole for the servo piston with the processing of the external pipe mounting flange of the supply / discharge passage in the same direction, which improves workability. Can be increased.

[Brief description of drawings]

1 to 3 relate to an embodiment of the present invention, and FIG. 1 is a vertical cross-sectional view of an oblique shaft type hydraulic rotary machine according to this embodiment, which is shown in the direction of arrow I--I in FIG. 2 is a left side view of FIG. 1, FIG. 3 is an enlarged view of a partly broken view showing a link mechanism and a valve plate from the left side of FIG. 1, and FIG. It is a longitudinal cross-sectional view showing a pressure rotating machine. 2 ... Rotary shaft, 3 ... Bearing, 4 ... Cylinder block,
5 ... Cylinder, 6 ... Piston, 7 ... Connecting rod, 10 ... Center shaft, 21 ... Casing,
22 …… Casing body, 23 …… Head casing, 24…
… Valve plate, 25 …… Tilt mechanism, 26 …… Cylinder chamber, 27 …… Servo piston, 28A, 28B …… Oil hole, 29 …… Pin, 30…
… Link, 31 …… Connecting pin, 33,34 …… Supply and discharge passage

Claims (2)

[Scope of utility model registration request] 1. A cylindrical casing having a head casing, a rotary shaft rotatably supported in the casing, a cylinder block provided in the casing and rotating with the rotary shaft, and a cylinder block. A piston reciprocally provided, one end of which is swingably supported by the rotary shaft, and one end surface of which is in sliding contact with the cylinder block, and the other end surface of which is slidable on the tilt sliding surface of the head casing. In a variable displacement oblique shaft type hydraulic rotating machine comprising a valve plate that abuts as much as possible and a tilting mechanism that tilts the valve plate together with the cylinder block, the tilting mechanism is a tilting minimum side of the valve plate. And a link mechanism that connects the servo piston and the valve plate to each other. A pair of supply / exhaust passages, which are located on both sides of the servo piston so as to sandwich the servo piston and extend in the same direction as the servo piston, are provided, and the inflow / outflow inlets of the respective supply / exhaust passages are tilted to the minimum. A variable capacity oblique shaft type hydraulic rotating machine that is opened to the side. 2. The servo piston is arranged so as to operate in a direction orthogonal to the axis of the rotary shaft, and the pair of supply / discharge passages are rotated so as to sandwich the servo piston in a lid wall portion of the head casing. The variable capacity oblique shaft type hydraulic rotating machine according to claim (1), wherein the utility model registration is provided in a direction orthogonal to the axis of the shaft.