JPS629075B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a power steering device for reducing the steering force of large vehicles such as construction vehicles and industrial vehicles.
More specifically, the present invention relates to a fully hydraulic power steering device that sends a certain amount of hydraulic fluid to power cylinders for steering wheels in accordance with the rotation of a steering wheel.

Conventionally, a control pump is driven by a handle;
2. Description of the Related Art A power steering device that generates a pressure difference between both ends of a control valve and operates the control valve using this pressure difference is known.
However, in this case, the input torque that must be applied to the steering handle to drive the control pump increases in proportion to the displacement of the control pump, and the frictional resistance of the internal mechanical links also increases, increasing the input torque. This results in an increase in

Also known is a power steering device of the type that is constituted by two rotation control valves and a special internal gear system, and in which the rotation control valves are directly switched by the steering handle shaft. In this device, the ring gear of the internal gear device is fixed to the housing, and the pinion is configured to roll while meshing with the ring gear, thereby increasing the amount of discharge. One is connected to the steering handle shaft, and the other is connected so as to extract only the rotation of the pinion. In this case, the liquid groove disposed on one side of the rotation control valve is limited by the number of teeth of the pinion. That is, the number of fluid control grooves extending in the axial direction on the rotation control valve must be equal to at least twice the number of teeth of the pinion and equally distributed on the circumference. Therefore, unless the rotation control valve is made extremely large, the internal leakage between the grooves will be too large to be ignored.

Furthermore, there is also a known device that uses a planetary gear as a speed increasing mechanism to increase the discharge amount, but in this case, the planetary gear is provided separately from the normal hydraulic motor for measuring fluid, so the entire device is It has the disadvantage of being large and expensive.

An object of the present invention is to eliminate the drawbacks of the conventional all-hydraulic power steering device as described above, and to provide an all-hydraulic power steering device that is relatively small, inexpensive, and capable of discharging a large capacity. There is a particular thing.

In order to achieve the above object, the present invention includes a ring gear 50 having internal teeth and a pinion 51 disposed within the ring gear 50 so as to form an expansion chamber and a contraction chamber while meshing with the ring gear. an input rotating shaft 20 connected to the ring gear 50; a gear device coupled to the ring gear 50 and the pinion 51 so as to abut against the sides thereof and rotate synchronously with the ring gear; The through hole 72 ~ which communicates with the space of each tooth bottom of
78 and said plate 52
a distribution valve 67 having ports abutted against each other and separately connected to an expansion chamber and a contraction chamber of the gear device;
a control valve consisting of a connecting shaft 58 connected between the pinion 51 and the movable valve via a universal joint, the movable valve 49 and the immovable sleeve 18 fitting the movable valve; Housing 6
The rotation of the pinion 51, which is provided on a relative rotation surface between the movable valve and the movable valve and includes a pin 53a projecting from the relative rotation surface and an elongated hole 80 that engages the pin 53a, is controlled by a certain angle. and a power cylinder 5 for applying deflection power to the steering wheels, and the control valve controls the hydraulic power source to one port of the distribution valve by continuously rotating the input rotation shaft 20. , the other port is connected to one chamber of the power cylinder 5, and the other chamber is connected to the oil tank 3.

An embodiment of the present invention will be described with reference to the drawings. In FIG. 1, 1 is a fully hydraulic power steering device, 2 is a main pump driven by an engine, etc., 3 is an oil tank, 4 is a relief valve, and 5 is a main pump driven by an engine or the like. is a power cylinder for steering the wheels.

To explain in more detail, connection port 7 to main pump 2, connection port 8 to tank 3, piping 1
Both end chambers 1 of the power cylinder 5 via 4 and 15
The housing 6 has ports 9 and 10 connected to the housings 6 and 17, respectively, and has cylindrical portions 13, 92, 12 having different diameters inside. A sleeve 18 is fitted into the cylindrical portion 12 and is non-rotatably connected to the housing 6 by a pin 19.

An end plate 94 that closes the cylindrical portion 12 is connected to the right end of the housing 6, and an end plate 93 having the cylindrical portion 11 and the shaft hole 91 is connected to the left end. The shaft hole 9
1, an input rotation shaft 2 rotated by a steering handle;
0 is supported and the end flange 2 of the input rotation shaft 20
0a is supported by the cylindrical portion 11 by a bearing 54 and a thrust bearing 24. The cylindrical portion 11 also accommodates a gear pump or gear device consisting of a ring gear 50 and a pinion 51 that meshes with the ring gear, and the ring gear 50 is rotatably coupled to the flange 20a with a pin 53.

As shown in FIGS. 1 to 3, a cylindrical valve 49 is fitted inside the sleeve 18 with a slight gap, forming a control valve as follows. That is,
Grooves 31 and 3 extending in the axial direction are formed on the outer periphery of the valve 49.
2, 34, a hole 33 that communicates the groove 32 with the hollow part 68
A thin hole 47 opening into the hollow portion 68 is provided.

As shown in FIG. 3, the holes 35, 36 and the holes 41, 42 provided in the sleeve 18 are spaced apart in the circumferential direction by a distance approximately equal to the width of the groove 31; , 46 and the holes 39, 40 are spaced from the groove 34, and the hole 37 and the hole 43 are spaced from the groove 32 by a distance approximately equal to the groove width in the circumferential direction. Also, hole 38 and hole 44
and are arranged at intervals smaller than the width of the groove 32. Further, the holes 35 and 39 correspond to the annular groove 25 provided in the housing 6, and the holes 41 and 45 correspond to the annular groove 26 provided in the housing 6.
The holes 36, 42 and the thin hole 47 are connected to the annular groove 27.
, the holes 43 and 46 are connected to the annular groove 28 and the holes 37 and 40
is aligned with the annular groove 29, and the holes 38 and 44 are aligned with the annular groove 30 in the circumferential direction.

As shown in FIG. 1, the cylindrical portion 13 contacts the side surfaces of the ring gear 50 and the pinion 51, and includes a plate 52 coupled to the ring gear 50 by a pin 53, and a distribution valve 67 in contact with the plate 52. mated. As shown in FIG. 4, the plate 52 is provided with through holes 72 to 78 communicating with the space at the bottom of the ring gear 50, that is, the expansion/contraction chamber.

As shown in FIG. 1, the distribution valve 67 has a semicircular groove 86 on its left side that intersects with the through holes 72 to 78;
87 (Fig. 6), and passages 26a and 25a on the left side.
The groove 86 has an annular groove 98 and an annular groove 98, respectively.
7 are connected to the annular groove 97 inside the distribution valve 67, respectively. Further, the distribution valve 67 is connected to the connecting shaft 58
has an eccentric hole 99 through which the pinion 51
rotates in synchronization with the revolution of A pinion 51 that rolls while meshing with the ring gear 50 is provided with a hole having a notch 55 in the center. A universal joint is constructed by inserting and supporting a pin 57, whose two ends are engaged with the notch 55, into a pin hole provided at the left end of the connecting shaft 58. Similarly, a pin 59 is inserted and supported through a pin hole at the right end of the connecting shaft 58,
A universal joint is formed by engagement with the notch 22 provided on the inner peripheral surface of the right end of the valve 49.

As shown in FIG. 5, a U-shaped centering spring 81 has its parallel ends inserted into a notch 82 provided in the valve 49, and its central curved portion is fitted and supported in a hole 84 provided in the housing 6. The elastic force of the parallel portions at both ends positions the valve 49 in a limited rotational direction with respect to the sleeve 18. As shown in FIGS. 1 and 5, the tip of the pin 53a connected to the right end of the valve 49 protrudes into the elongated hole 80 provided in the end plate 94, and the relative rotation of the valve 49 with respect to the housing 6 is controlled at a certain angle. It constitutes a mechanism to limit the range.

Next, the operation of the power steering system according to the present invention will be explained. When there is no input from the steering wheel, that is, in a neutral state, the valve 49 is in the position shown in FIG. 2 by the centering spring 81, and the main pump The hydraulic oil discharged from port 7, passage 7a, annular groove 27, small hole 48, 4
7, hollow part 68, hole 33, groove 32, hole 38, 4
4. The oil reaches the port 8 via the annular groove 30 and the passage 8a, and is further returned to the oil tank 3.

Now, when the handle is turned to the right, the ring gear 50 is rotated through the flange 20a of the input rotation shaft 20.
When the power cylinder 5 is loaded, the gear pump composed of the ring gear 50 and the pinion 51 does not perform a discharge action, and the ring gear The pinion 50 and the pinion 51 are rotated slightly to the right against the centering spring 81 while being integrated. At the same time, the valve 49 connected to the pinion 51 and the connecting shaft 58 also rotates in the right direction (in the direction of the arrow in FIG. hole 42, groove 31,
The annular groove 97 is reached through the hole 41, the annular groove 26 and the passage 26a, and the through holes 72, 7 are reached by the distribution valve 67.
3 and 74 into the pump chamber, and rotates the pinion 51 to the left (to the right in FIG. 4). At the same time, the through holes 76, 77, 78 connected to the remaining pump chamber
The hydraulic oil discharged from the pipe flows into the annular groove 98 by the distribution valve 67, and further flows through the passage 25a, the annular groove 25, the hole 39, the groove 34, the hole 40, the annular groove 29, and the passage 1.
It reaches the port 10 via 0a, and flows into one chamber 17 of the power cylinder 5 from the piping 15. The hydraulic oil discharged from the other chamber 16 of the power cylinder 5 is transferred from the pipe 14 to the port 9, the passage 9a, and the annular groove 2.
8, the hole 43, the groove 32, the hole 44, the annular groove 30, and the passage 8a to reach the port 8 and return to the oil tank 3.

When the handle is operated continuously, the pinion 51
The ring gear 50 remains stopped at the position where the valve 49 has been rotated by a certain angle, that is, the position where the valve 49 has been switched.
rotates while meshing with the pinion 51, driving the power cylinder 5 to the left and deflecting the wheels to the right.

Also, when the handle is stopped, the ring gear 50
stops, and the pinion 51 is rotated to the right by the force of the centering spring 81 while meshing with the ring gear 50, returning the valve 49 to the neutral position.

When the steering wheel is turned to the left, the operation of the power steering device is reversed depending on the direction of rotation of the input rotating shaft, and the wheels are steered in the opposite direction.

If pressurized hydraulic oil is no longer supplied to the device due to a failure of the main pump 2, etc., the pinion 51 is inserted into the elongated hole 80 formed in the end plate 94 by the pin 53a.
It rotates until it hits the inner wall of the body and does not rotate any further. Therefore, when the handle is further turned, the ring gear 50 rotates while meshing with the pinion 51, and discharges the hydraulic oil. That is, in this case, the ring gear 50 and the pinion 51 automatically constitute a manual pump, and the hydraulic oil can be supplied to the power cylinder 5.

As described above, in the fully hydraulic power steering device according to the present invention, the grooves 31 and 34 can be arranged at any desired interval, and the intervals between the annular grooves 25 to 30 inside the housing 6 can also be set at any desired interval. As a result, internal leakage can be extremely reduced. Also,
Since there is no need to specially install a speed increasing mechanism, it is easy to design a relatively small and inexpensive device.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a power steering device according to the present invention, FIG. 2 is a cross-sectional view taken along the line - in FIG. 1,
Fig. 3 is a developed view for explaining the operation of the valve groove of the valve and the valve hole of the sleeve of this device, Fig. 4 is a cross-sectional view taken along the line of Fig. FIG. 6 is a cross-sectional view taken along line - of FIG. 1. 1: Hydraulic power steering device, 2: Main pump, 3:
Oil tank, 5: Power cylinder, 6: Housing, 18: Sleeve, 20: Input rotating shaft, 25~
30: Annular groove, 31, 32, 34, 86, 87:
Groove, 33, 35-48: Hole, 49: Valve, 5
0: Ring gear, 51: Pinion, 52: Plate, 53, 53a: Pin, 54: Bearing, 58: Connection shaft, 67: Distribution valve, 72-78: Through hole, 80:
Long hole, 81: Centering spring.

Claims (1)

[Claims] 1. A gear device consisting of a ring gear 50 having internal teeth and a pinion 51 disposed within the ring gear 50 so as to form an expansion chamber and a contraction chamber while meshing with the ring gear; the ring gear 5
0; an input rotation shaft 20 connected to the ring gear 50 and the pinion 51; coupled to rotate in synchronization with the ring gear; and communicates with the space at the bottom of each tooth of the ring gear 50; a plate 52 having through holes 72 to 78; a distribution valve 6 having ports abutting the plate 52 and respectively connecting to the expansion chamber and the contraction chamber of the gear device;
7; a connecting shaft 58 connected via a universal joint between the pinion 51 and a movable valve; a control valve comprising the valve 49 and an immovable sleeve 18 fitting the valve; ; a pin 53a provided on a relative rotation surface between the housing 6 and the valve and protruding from the relative rotation surface;
The pinion 5 consists of a long hole 80 that engages a.
a mechanism for restricting the rotation of 1 to a certain angular range; a power cylinder 5 for applying deflection power to the steering wheels;
The control valve connects a hydraulic power source to one port of the distribution valve and the other port to one chamber of the power cylinder 5 by continuous rotational operation of the input rotation shaft 20; A fully hydraulic power steering device, the other chamber of which is connected to the oil tank 3.