JPH0117496Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention relates to a power steering system, and is especially
This invention relates to an improvement of the power steering device known from publication No. 55-50820.

As shown in FIG. 1, this type of power steering system has a worm shaft 3 connected via a torsion bar 2 to an input shaft 1 that is rotationally driven in conjunction with a steering wheel (not shown) in the driver's seat. The rotation of the worm shaft 3 is converted into the axial reciprocating motion of the piston 5 by the guide mechanism 4, and the reciprocating motion of the piston 5 is transmitted to the output shaft 7 via the sector gear 6 to rotate the output shaft 7.
The rotation of the output shaft 7 causes an axle (not shown) to swing, and fluid pressure is introduced into the pressure chambers 8 and 9 provided at both ends of the piston 5 at appropriate times to control the axial direction of the piston 5. It is designed to amplify the driving force. The supply of fluid pressure to the pressure chambers 8 and 9 is restricted by a spool valve 10 interlocked with the input shaft 1.

As shown in FIGS. 2 and 3, a guide groove 11 extending in the axial direction is formed on the outer periphery of one end of the input shaft 1.
A pawl 12 that engages is radially passed through. A ring 13 is fitted around the outer periphery of one end of the spool valve 10, and a spiral groove 14 is formed on the inner surface of the ring 13. The ball 12 is engaged with the spiral groove 14, and when the input shaft 1 rotates,
The ball 12 slides along the spiral groove 14 and reciprocates the spool valve 10 in the axial direction. A valve sleeve 18 having ports 15, 16, and 17 is fitted around the outer periphery of the ring 13 and the spool valve 10, and this valve sleeve 18 is connected to the worm shaft 3. port 15,1
6 and 17 communicate with the pressure chamber 8, a fluid pressure source (not shown), and the pressure chamber 9, respectively, and the spool valve 10
by its axial movement, causes port 16 to communicate with port 15 or 17 or port 1
6 and 17 from port 15.

The torsion bar 2 twists when the input shaft 1 rotates, and the piston 5 does not move in the axial direction until fluid pressure is introduced into the pressure chamber 8 or 9, without directly transmitting the rotation of the input shaft 1 to the worm shaft 3. Move to. Along with this movement of the piston 5,
The worm shaft 3, the valve sleeve 18 and the ring 13 rotate together, whereby the torsion bar 2 is untwisted and the spool valve 10 is moved to a neutral position that blocks the port 16 from the ports 15 and 17. . Therefore, the time when the torsion bar 2 is untwisted and the time when the spool valve 10 reaches the neutral position must be the same time. Then, the positional relationship between the torsion bar 2 and the spool valve 10 was adjusted. The ring 13 and the valve sleeve 18 were connected so that they could not rotate relative to each other by a pawl 20 passing through them.

Therefore, in the past, it was difficult to adjust the positional relationship between the torsion bar 2 and the spool valve 10 after driving the pin 19, resulting in defective products due to incorrect pin driving, and the possibility of changing the neutral position during the use of the power steering device. There were problems such as the complexity of correcting misalignment, and the reassembly work of the power steering device was also complicated.

This invention was devised to solve these conventional problems, and the object thereof is to provide a power steering device that can extremely easily adjust the positional relationship between the torsion bar and the spool valve.

The power steering device according to this invention has a ring and a valve sleeve connected by an adjustment mechanism.

Next, an embodiment of the power steering device according to this invention will be described based on the drawings.

4 to 6, an engagement groove 21 extending in the axial direction is provided on the outer periphery of the ring 13 in the power steering device, and an offset pin that engages with the engagement groove 21 is provided in the valve sleeve 18. 23 is provided as an adjustment mechanism. Offset pin 2
3 has an engaging protrusion 25 that is screwed into the valve sleeve 18 at a male thread 24 and is eccentric with respect to the central axis of the male thread 24. Engagement protrusion 2
5 is engaged with the engagement groove 21, and the offset pin 23
By this rotation, the engagement protrusion 25 can rotate the ring 13 in the circumferential direction in the engagement groove 21.

The power steering device supports the piston 5 so as to be slidable in the axial direction, supports the valve sleeve 18 so as to be rotatable in the circumferential direction, and has the pressure chambers 8 and 9 formed to face both end surfaces of the piston 5, respectively. The housing 26 includes a communication hole 27 communicating with the ports 15, 16, and 17, a pressure introduction hole 28, and a communication hole 2.
9 is drilled. (See Figure 2) Furthermore, the housing 26 is provided with an opening 33 that allows the offset pin 23 to be rotated from outside the housing 26, and the offset pin 23 is provided with a slot 30 that can be engaged with a driver. By inserting a driver through the opening 33, the offset pin 23 can be easily rotated.

After adjusting the positions of the torsion bar 2 and the spool valve 10, a punch is driven into the threaded joint between the offset pin 23 and the valve sleeve 18 (the punch driven part is indicated by the symbol A in FIG. 5).
This prevents the offset pin 23 from rotating.

Due to the rotation of the ring 13 relative to the valve sleeve 18, the torsion bar 2 and the spool valve 1 are
0, and even after the pin 19 is driven in, the positional relationship between the torsion bar 2 and the spool valve 10 can be easily adjusted from outside the housing 26.

A blind lid 31 is screwed into the opening 33, and the blind lid 31 is fixed with a lock nut 32.

As mentioned above, the power steering device according to this invention has the excellent effect that the positional relationship between the torsion bar and the spool valve can be adjusted extremely easily because the ring and the valve sleeve are connected by the adjustment mechanism. have

Note that this invention is not limited to the above-mentioned embodiment, and the following modifications are possible.

(i) A configuration in which a worm gear is formed on the outer periphery of the ring, a worm that meshes with the worm gear is attached to the valve sleeve, and the worm is rotated through the same opening as in the previous embodiment.

(ii) A configuration in which a lock nut is used as a means for fixing the offset pin.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing a conventional power steering device, Fig. 2 is an enlarged view showing the spool valve in Fig. 1 and its surroundings, Fig. 3 is a sectional view taken along the - arrow line in Fig. 2, Fig. 4 is a sectional view similar to Fig. 3 showing an embodiment of the power steering device according to this invention, Fig. 5 is a sectional view taken along the - arrow line in Fig. 4, and Fig. 6 is the same embodiment. FIG. 3 is a perspective view showing an offset pin in FIG. Note that the same or corresponding parts in the figures are indicated by the same reference numerals. 1...Input shaft, 2...Torsion bar, 3...
Worm shaft, 4...Guide mechanism, 5...Piston,
6... Sector gear, 7... Output shaft, 8, 9... Pressure chamber, 10... Spool valve, 11... Guide groove,
12... Ball, 13... Ring, 14... Spiral groove, 15, 16, 17... Port, 18... Valve sleeve, 19... Pin, 20... Ball, 2
1... Engagement groove, 22... Valve sleeve, 23...
... Offset pin, 24 ... Male thread, 25 ... Engagement protrusion, 26 ... Housing, 27, 29 ... Communication hole, 28 ... Pressure introduction hole, 33 ... Opening, 30
...Slot split, 31...Blind lid, 32...Lock nut, A...Punch driving part.

Claims (1)

[Scope of utility model registration request] an input shaft that is rotatably driven in conjunction with a handle on a driver's seat; a worm shaft that is arranged concentrically with the input shaft on an extension of the input shaft; a torsion bar that connects the worm shaft and the input shaft; a piston fitted around the outer periphery of the worm shaft, a guide mechanism interposed between the piston and the worm shaft and guiding the piston in the axial direction according to rotation of the worm shaft, and a guide mechanism perpendicular to the piston. an output shaft in a twisted position, a sector gear that rotates integrally with the output shaft around the output shaft and meshes with the piston, and a spool valve that is slidably fitted on the outer periphery of the input shaft. a ring fitted onto one end of the spool valve and having a spiral groove formed on its inner surface; an engaging body that radially penetrates the one end of the spool valve and is engaged with the spiral groove; a guide groove that is bored in the input shaft in the axial direction and that accommodates the engaging body so as to be slidable in the axial direction; a guide groove that is fitted around the ring and the spool valve so as to be rotatable in the circumferential direction; a valve sleeve that is connected so as not to be relatively rotatable in the direction; and a pair of pressure chambers that slidably support the piston in the axial direction and rotatably support the valve sleeve in the circumferential direction, and that are opposed to both end surfaces of the piston. a housing forming a housing, a pressure introduction hole opened in the housing so as to face the outer peripheral surface of the valve sleeve and connected to a hydraulic power source, and a pressure introduction hole adjacent to the pressure introduction hole and opposite to the outer peripheral surface of the valve sleeve. a pair of communication holes opened in the housing and communicated with each of the pressure chambers, and three ports passing through the valve sleeve in the radial direction and corresponding to the pressure introduction hole and each communication hole, respectively. A power steering device, characterized in that the valve sleeve is provided with an adjustment mechanism that can rotate the ring in the circumferential direction relative to the valve sleeve and can fix the ring in a predetermined position.