SU1322972A3 - Device for limiting turn of segment gear in hydraulic steering system with booster - Google Patents

Abstract

A travel limiting device for hydraulic power steering is constituted by two valve members (31, 35, 36, 37) which are inserted in respective exhaust ducts (21, 22, 23, 24, 25) for fluid under pressure, and are housed in the wall (18) of the power steering cylinder (1) beside a sector gear (4) which drives the steering shaft. These valve members (31, 35, 36, 37) are actuated by respective operating rods (41) with free ends (44) which project into the cylinder (1) in positions such that one is engaged by a respective side (52, 53) of the sector gear (4) in each of the end of travel positions of the maximum allowed steering. <IMAGE>

Description

1 cylinder with internally mounted piston 2 with seals, sector gear A and screw 10, mounted axially inside the piston cavity and connected by reversing connection with nut II, two valves located in the wall of the cylinder body 1 and made normally closed and pressed spring to interact through the working rods with the side surfaces of the sector gear A. The working rods are made with the ability to move in the axial direction, with

The invention relates to a transport engineering, namely to devices for limiting the rotation of a sector gear in a hydraulic power steering,

The object of the invention is to facilitate the adjustment of the limiter for hydraulic power steering, which allows direct adjustment during assembly of only the mechanical parts of the machine without fluidizing the installation and operation of the hydraulic system parts.

Fig. I is a power steering device with a motion limiter, a vertical longitudinal section; FIG. 2 is a section A-A in FIG. 1; Fig. 3 is a detail of the device for restricting movement, shown in the position of maximum control.

The housing 1 of the steering cylinder includes a piston 2 with a toothed rack 3, as well as a sector gear 4 mounted on a key on the shaft of the steering gear 5 and engaged with the toothed rack.

Typically, the piston 2 divides the cylinder into two working chambers 6 and 7, connected alternately through the valve 8 to the source of pressurized fluid and to the outlet, in accordance with the known and conventional method

The piston 2 contains axially to the cam 9, in which the screw 10 moves,

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than at their ends, interacting with the side surfaces of the sector gear, spherical caps are installed to interact with the corresponding grooves made on the side surfaces of the sector gear, and with the end surface of the valve body. When reaching the position of limiting the rotation of gear 4, the corresponding cap opens the valve element to communicate the pressure hydraulic line with the drain, thereby providing unloading of the pump, 3 sludge.

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which is engaged with the nut 1I, which is connected via the pivoting lever 12 to the thrust 13 of the hydraulic distributor 8,

The end 14 of the screw 10 protrudes from the cylinder 1 through the end wall 15 which is made in the form of a removable cover and can be connected to a known steering wheel (not shown),

The piston 2 has a passage 16 for maintaining a constant hydraulic connection between the chamber 6 and the cavity 17 of the cylinder 1 containing the sector gear 4,

The wall 18 of cylinder 1 has two through holes 19 and 20 with internal thread and located symmetrically with respect to the axis of the sector gear 4 and perpendicular to the axis of cylinder 1. Holes 19 and 20 have corresponding cylindrical broadening 21 and 22 interconnected through a passage 23, formed inside the wall 18 of the cylinder 1, Passage 23 is also connected to the sections of the channel 24 and 25, which. made inside the walls 26 and 27 of cylinder 1 and out into. Chamber 7 is opposite to chamber 6 through the opening. Tie 28.

The first valve element of the movement restriction device according to the invention is placed in the threaded bore 19, Second valve 31322972

A pan element (similar to the first one) is placed on a threaded bore 20. A tubular housing 5, 31 having a first axial hollow part 32, a second axial hollow part 33 connected to the preceding part is engaged with the threaded bore 19 by means of a connecting thread 29 and 30. and the third hollow part 34. The floor part 33 has a smaller diameter than the part 32, which defines the valve seat 35, against the latter valve 36 of the valve element abuts. This valve 36 is held continuously against the saddle 35 and therefore it is held in the closed position by means of a coil spring 37 in the hollow part 32, which has a threaded inner wall 38. The threaded wall of this 0 part is engaged with the nut 39, which acts as a shoulder for springs 37, providing regulation of its load

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Centered with the valve seat 35 is placed a diametral passage 40 for extending the axially hollow portion 32 to connect with a widening 21 of the aperture 1 9.

The working rod 4 is placed in the axial hollow part 33 and is loosely connected at one end to the flap 36, and at the other end to the shank 42 of the housing 43, which is placed in the axial cavity 34 with a radial clearance and is made with a spherical cap 44 outside the housing 31. .

The axial hollow portion 33 is provided with a diametral passage 45, which holds the internal cavity of this portion in constant connection with the chamber 7 of housing I.

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At the end 42 of the housing 43 there is a flange 47 fixed to the fingers 46 and an annular groove 48 formed in accordance with the radial retaining fingers 46. The flange 47 engages the fingers 46, holding the Q body 43 in place, while the annular protrusion 49 of the hollow axial part 34 forms a shock surface on the housing 43 itself in accordance with the specific method of operation.

The toroidal sealing washer 50 forms a hydraulic seal between the housing 31 and the wall 18 qi5 O 0

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The lindra 1, and the cap with thread 51 ensures the fastening and protection of the opposite end of the housing 31.

The valve element that is inserted into the opening 20 is exactly the same as the element that is inserted into the opening 19.

On the surfaces 52 and 53 of the sector gear, corresponding grooves 54 and 55 are formed with curved surfaces having the same radius as the spherical caps of 44 valve elements, which for brevity are defined as right and left.

The device for limiting movement works as follows.

Assume that piston 2 moves to the right (Figs. 1 and 2) and the sector gear moves at an angle in the clockwise direction. The chamber 6 and the cavity 17 of the housing 1 are under ;; However, the chamber 7 is connected to the outlet of the usual 1PLM by way of the distributor 8.

During this duplication, since the position for restricting movement was not reached, the right and left valves are closed.

Indeed, the corresponding valves 36 close the valve seats 35 so that hydraulic fluid cannot pass from cavity 17 into the hollow axial parts 32 and out of them through diametral passage 40, hole 20 and cylindrical broadening 21B passage 23 and channels 24 into chamber 6, which is connected with an outlet.

The spherical caps 44 of both valves are located at the maximum entrance to the cavity 17 with flanges 47 at the ends abutting the fingers 46 and therefore lifted a certain distance S from the surfaces formed by the annular projections 49.

Upon reaching the position of restriction of movement, which corresponds to the position-. driving in the direction currently being considered, the groove 55 with a curved surface on the side 53 of the gear 4 is mechanically engaged with the spherical cap 44 of the right valve turned.

As a result, further corner. In the motion of the gear wheel, the cap 44 is pressed down and carries the

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The barrel pin 41 with the flap 36 is open to the side of the seats 35 and overcomes the force given by the spring 37, which usually exceeds the fluid pressure in the cylinder.

When the clan seat 35 is opened, the subnet 17 of the cylinder 1, which is under pressure, immediately communicates with the chamber 7 and hence the outlet. The movement of the piston 2 stops automatically as a result of the creation of special conditions for the hydraulic system.

If sector gear 4 should move further in the direction of the clock hand as a result of manual control of the screw 10 after moving the cap 44 over a distance, then it could not have done this because of the mechanical stop of the body 43 against the annular protrusion 49.

The movement of the piston 32 is also blocked as a result of mechanical conditions, KOTfipbie provide a safe stop in the position of restriction of movement.

The device for limiting movement in accordance with the invention stops the screw 10 by both hydraulic and mechanical means, as a result it is maximally guaranteed that the control elements are damaged in the positions of maximum control. In addition, external mechanical limiters of the movement become superfluous. occurs when piston 2 moves to the left.

When a position is reached to restrict movement 1 into the spherical groove 54 of the sector gear 4, enter the 4th cap 44 of the left valve, creating similar conditions for operation as it is.

Since, under the conditions considered, chamber 7 is under pressure and chamber 6 is in the discharge position, cavity 17 also communicates with the outlet through passage 16.

When opening the left clan seat 35, the hydraulic fluid in Chamber 7 can pass into the cavity 17 and then into the outlet through the channels 24 and 25, the axial part 33 and the hole 20, the passage 40, the axial part 33 and another passage 45.

The gchpagodlr design and operation of valve elements to limit

Their movements can be adjusted purely mechanically until the hydraulic components of the system are mounted on the vehicle and before the engine is running.

Indeed, their regulation is achieved only by precise axial placement of the housings 31 inside the holes 19 and 20 after installing the sector gear in the appropriate positions of the maximum allowable mechanical movement and after firm seating in the grooves 55 and 54 of the gear 4 of the caps 44 of the right and left klagtanov.

Claims (1)

Invention Formula 0 0 A device for restricting rotation of a sector gear in a hydraulic power steering, comprising a cylinder body with an internal mounted piston with seals forming two 5 opposite working chambers, a hydraulic distributor hydraulically connected to both chambers, a kosos and a hydraulic tank, a drive shaft for turning the wheels of the vehicle, a sector gear fixed with a spindle on the shaft with the possibility of engagement with a rail mounted on the piston, a screw mounted axially inside the piston cavity and connected by means of a reversible connection with a nut installed at one end of the piston with the possibility of ensuring its limited rotation and movement of the gold peak the valve and two valve elements that are inserted into the holes communicated with the hydraulic tank and located in the wall of the cylinder body behind the sector gear,  moreover, the free end of the screw protrudes axially with the seal from the cylinder body for connection with the element of the steering seal, the valves are of a normally closed type and Q podrkat spring to interact through the working rods with the side surfaces of the sector gear, and the working rods are movable in axial direction, characterized in that, in order to facilitate adjustment, at the ends of the working rods interacting with the lateral surfaces of the sector gear, ...-. five 0 five actions with corresponding skinny depressions made on the lateral surfaces of the valve body. 1 five TO g  §