JP2003028305A - Sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing device that does not damage an O-ring when a plug member is inserted in a steering body. SOLUTION: In a state that a plug member 25 is attached to an opening portion 7c of a steering body 7, a screw portion 28 is formed on surfaces on which the plug member 25 and the opening portion 7c are opposed to each other. An annular groove 29a storing an O-ring 29 one of the surfaces on which the plug member 25 and the opening portion 7c are opposed to each other. In this sealing device, the screw portion 28 provided on an outer peripheral portion of the plug member 25 and an inner peripheral portion of the opening portion 7c, and an annular groove 29a provided on one thereof have a positional relationship preventing the O-ring 29 stored in the annular groove 29a from interfering a screw portion 28b provided on the other side when the plug member 25 is attached to the opening portion 7c.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing device for maintaining liquid tightness between a container for containing a liquid and a lid member for closing the container, and more particularly, a container and the lid member are screwed together. And a ring-shaped seal member.

[0002]

2. Description of the Related Art Generally, a sealing device provided to prevent the liquid contained in a container from leaking to the outside has a screw portion on the container side and on a lid member side for closing an opening of the container. It is provided, and the two members are coupled to each other by being screwed with each other by the screw portion. Further, between the container and the lid member, an O-ring for keeping the liquid tightness of both members is compressed and held.

For example, Japanese Unexamined Patent Publication No. 9-315326 discloses a seal device used in a rack and pinion type power steering device to prevent the steering body and pressure oil in the steering body from leaking to the outside. The plug member and the plug member are provided.

[0004]

In such a conventional sealing device, a threaded portion formed at the open end of the steering body as a container and a threaded portion formed at a position corresponding to this threaded portion are provided. A plug member that serves as a lid member is screwed into the opening end of the steering body. Further, an O-ring is provided in the annular groove formed on the outer peripheral portion of the plug member to maintain liquid tightness between the steering body and the plug member. However, since the O-ring is provided inside the threaded portion of the plug member, the O-ring may come into contact with the threaded portion of the plug member when the plug member is inserted into the steering body. Generally, since the tip of the thread is sharply pointed, there is a possibility that the O-ring may be damaged when the O-ring comes into contact with the thread, and in this case, there is a problem that the sealing effect is deteriorated.

The present invention has been made to solve such a problem, and provides a sealing device which does not damage an annular sealing member such as an O-ring when a lid member such as a plug is mounted on a container. To provide.

[0006]

In order to achieve the above-mentioned object, a sealing device according to claim 1 of the present invention is a container for containing a liquid and having a container, and a container having an opening for closing the container. A lid member mounted from the outside, and in a state where the lid member is mounted in the opening of the container, the lid member is formed on the outer peripheral portion of the lid member and the inner peripheral portion of the opening, which are surfaces facing each other, A threaded portion for screwing the two together, and an annular groove for accommodating the annular seal member, the annular groove being provided on one of the outer peripheral portion of the lid member and the inner peripheral portion of the opening, which are surfaces facing each other. In the sealing device having the screw portion and the annular groove, when the lid member is mounted in the opening portion, the annular sealing member housed in the annular groove is the outer peripheral portion of the lid member and the opening portion. Does not interfere with the screw part provided on the other inner peripheral part of It characterized in that in the location relationship.

The seal device according to claim 2 of the present invention comprises:
The annular groove and the annular seal member are provided on the outer peripheral portion of the lid member and outside the threaded portion of the lid member.

The sealing device according to claim 3 of the present invention is
A taper surface is formed on a surface that is provided on the other of the outer peripheral portion of the lid member and the inner peripheral portion of the opening, and intersects with the annular seal member when the lid member is attached to the opening of the container. It is characterized by

The seal device according to claim 4 of the present invention is
It is characterized in that it has a fitting portion which is provided on an outer end surface of the lid member and which fits with a lid member mounting tool for screwing the lid member into the container.

The sealing device according to claim 5 of the present invention is
The container is a valve housing of a control valve for a power steering device that switches an oil supply passage of oil to a power cylinder by rotation of a steering shaft, and the lid member is a plug member screwed into the valve housing. Characterize.

[0011]

According to the sealing device of the first aspect of the present invention, when the lid member is inserted into the container, the sealing device is provided at one of the outer peripheral portion of the lid member and the inner peripheral portion of the opening of the container. Since there is no risk of the annular seal member coming into contact with the threaded portion provided on the other side, damage to the seal can be prevented.

According to the sealing device of the second aspect of the present invention, since the annular seal member is provided outside the screw portion, the liquid pressure in the container applied to the seal portion is reduced by the screw portion. Become. The durability of the annular seal member is improved.

According to the third aspect of the present invention, when the lid member is inserted into the container, the lid member or the annular seal member provided at the opening of the container slides on the tapered surface. The gradual compression / expansion deformation facilitates insertion of the lid member into the container. Further, since no corner is formed at the inner peripheral end of the opening of the container or the outer peripheral part of the lid member, there is no possibility of damaging the annular seal member at this corner.

According to the sealing device of the fourth aspect of the present invention, when the lid member is screwed into the container, the lid member mounting tool is fitted to the fitting portion provided on the outer end surface of the lid member. Therefore, there is no risk that the lid member mounting tool will come into contact with the annular seal member provided on the outer peripheral portion of the lid member, and damage to the annular seal member can be prevented.

In the control valve for a power steering device, it is necessary to provide a seal member separately between the plug member and the valve shaft, and care must be taken when assembling. However, according to the sealing device of the fifth aspect of the present invention, since the annular seal member provided between the plug member and the valve body that houses the plug member has almost no risk of damage during assembly, The burden on the operator can be reduced.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows an embodiment of a rack and pinion type power steering apparatus according to the present invention, FIG. 2 is an enlarged view of a main part thereof, and FIG. 3 is a plug member 25 described later.
FIG. In these figures, the reference numeral 1 as a whole is the power steering device main body in the rack and pinion type power steering device. Reference numeral 2 denotes a stub shaft serving as an input shaft connected to a steering handle (not shown), and 3 denotes a pinion shaft connected to an inner end side of the stub shaft 2 via a torsion bar 4, and the pinion shaft 3 has an illustration. A pinion tooth 3a that meshes with a rack tooth 5a on the rack 5 that constitutes a steering link mechanism is provided. A safety spline portion 6 consisting of a protrusion and a groove is interposed between these two shafts 2 and 3 as a fail-safe mechanism that allows relative rotational displacement within a predetermined angle range due to torsion of the torsion bar 4. Is provided.

The torsion bar 4 has an inner end press-fitted and fixed to the pinion shaft 3 side and an outer end stub shaft 2.
It penetrates through the inside and extends to the outer end side of the stub shaft 2. Further, in the serration portion 2a for coupling with the steering handle side of the stub shaft 2, the stub shaft 2 and the torsion bar 4 are connected by a dowel pin 2b.

Reference numeral 7 denotes a steering body constituting the power steering main body 1, which is a rotary flow path switching valve 1 described later.
0 is housed in the valve housing portion 7a (the valve housing in claim 5) and the gear housing portion 7b is housed in the pinion shaft 3 and the rack 5. The valve housing portion 7a constitutes the container of the present invention. The two shafts 2 and 3 are rotatably supported by a shaft support which is directly received by a bearing or a steering body 7 which will be described later, and an oil seal is interposed at an appropriate position.

A rotor 11 and a sleeve 12 constituting a rotary flow path switching valve 10 are integrally connected to the inner ends of the shafts 2 and 3 in the steering body 7. These rotor 11 and sleeve 12
The oil pump P, the oil tank T and the power cylinder left chamber CL, the right chamber C (not shown)
It is well known that the flow path switching between R and R is performed.
The rotor 11 is integrally formed on the stub shaft 2 side, the sleeve 12 is integrally formed on the pinion shaft 3, and the sleeve 12 is combined by the torsion bar 4 in a relatively rotationally displaceable manner. It is installed in the built-in space 8 at 7a.

Is the structure of the rotor 11 and the sleeve 12 constituting the rotary type flow path switching valve 10, and the hydraulic circuit in the valve housing portion 7a the same as that of a known one?
Or something similar. On the outer peripheral surface 11a of the rotor 11 and the inner peripheral surface 12a of the sleeve 12, which face each other and are in sliding contact with each other, a plurality of passage grooves are provided at predetermined intervals in the circumferential direction, and valve grooves 13a, 13b, 14a, 14b are provided.
And a plurality of fluid supply holes and fluid discharge holes are formed at appropriate places, and the hydraulic circuit is switched as necessary by selectively connecting and disconnecting these passage grooves and the like. Controlled.

In the figure, 15 and 16 are inlet ports into which the pressure oil from the oil pump P flows and outlet ports for returning the pressure oil to the oil tank T, 17a and 17b.
Is a left output port and a right output port connected to the left chamber CL and the right chamber CR of the power cylinder, which are rotational displacements due to the steering operation of the rotary flow path switching valve 10 described above, and hydraulic passages between these ports. Is arbitrarily connected and cut off to control the generation of steering assist force in a power cylinder (not shown).

Further, in this embodiment, the sleeve 12 constituting the rotary type flow path switching valve 10 is provided integrally with the pinion shaft 3, and the pinion shaft 3 is axially supported by the ball bearing 21 and the bush 22. There is.

The ball bearing 21 described above has a small diameter portion 1 whose inner race is formed at the end of the sleeve 12.
The outer race is pressed into 2c and abuts on a step portion 21a formed on the inner peripheral surface of the assembling space 8 and is locked by an inner end of a plug member 25 described later.

Reference numeral 25 is a plug member which constitutes the lid member of the present invention, and is screwed with the valve housing portion 7a by the screw portion 28 to open the opening 7c of the steering body 7.
Is blocking. The threaded portion 28 is formed on the plug member side threaded portion 28a provided on the outer peripheral surface of the plug member 25 and the built-in space 8 of the valve housing portion 7a, that is, on the inner periphery of the opening 7c of the steering body 7. It is composed of a housing side screw portion 28b. An opening for penetrating and holding the stub shaft 2 is formed on the inner peripheral side of the plug member 25, and an oil seal 26 is interposed between the opening and the stub shaft 2. The oil seal 26 causes the stub shaft 2 to move to the valve housing portion 7a.
It is rotatably inserted therein and sealed. On the other hand, an oil seal 27 is also provided in the middle portion of the pinion shaft 3. The working oil is filled between the oil seals 26 and 27.

Reference numeral 29 is an O-ring, which constitutes the annular seal member of the present invention. The O-ring 29 is an outer peripheral portion of the plug member 25, and is an annular groove 29 formed outside (on the upper side in the drawing) of the plug member side screw portion 28a.
It is provided in a. This O-ring 29 is previously provided with the annular groove 2.
9a, and the plug member 25 is compressed and deformed when it is inserted into the assembling space 8 to seal between the valve housing portion 7a and the plug member 25. Thus, since the O-ring 29 is provided outside the screw portion 28a, the hydraulic pressure generated inside the valve housing portion 7a is first reduced by the screw portion 28a. This is the screw part 28a
This is due to the labyrinth effect of. Since the hydraulic pressure that has passed through the screw portion 28a is applied to the O-ring 29 in a reduced pressure state, the durability of the O-ring 29 can be improved.
Further, a taper portion 30 is formed at the outer end of the built-in space 8, and when the plug member 25 is inserted, the O-ring 29 is gradually compressed and deformed while sliding on the surface of the taper portion 30. It becomes easy to insert 25 and O
The ring 29 is prevented from being damaged.

Reference numeral 31 is a fitting hole into which a tool for screwing the plug member 25 into the valve housing portion 7a (hereinafter referred to as a plug member mounting tool, which constitutes a lid member mounting tool in the present invention) is fitted. Is. Although not shown, the fitting hole 31 has a concave shape having a polygonal cross section. A plug member mounting tool having a shape corresponding to the fitting hole 31 is fitted into the fitting hole 31 and the screw portion 28 is tightened, whereby the plug member 25 is attached to the valve housing portion 7a.
It is screwed to. At this time, the plug member attaching tool only contacts the fitting hole 31 and does not touch the outer peripheral surface of the plug member 25, so that the O-ring 29 is not damaged by the plug member attaching tool.

According to the structure of the above-described embodiment, since the O-ring 29 is provided outside the plug member side screw portion 28a, when the plug member 25 is inserted into the valve housing portion 7a, the O ring is inserted. Since the ring 29 does not come into contact with the valve housing side threaded portion 28b, there is no risk of damaging the O-ring 29 by the threaded portion 28b. Therefore, the assembler needs to use the oil seal 26 and the O ring 29.
Since it is not necessary to pay attention to both of them, there is also an effect that the burden on the operator is reduced.

Next, another embodiment of the present invention will be described with reference to FIG. FIG. 4 shows another embodiment of the rack and pinion type power steering apparatus according to the present invention, and the description of the same configuration as the above-mentioned configuration will be omitted.

Reference numeral 35 denotes a plug member, which has the same function as that described above, but in the present embodiment, a plug member side screw portion 38a is formed at the upper end portion of the plug member 35. On the other hand, similarly, the valve housing side threaded portion 38b provided on the valve housing 7a is also formed at the upper end portion of the built-in space 40 of the valve housing portion 37a and screwed with the plug member side threaded portion 38a.

An O-ring 39 is provided in an annular groove 39a formed on the inner side (lower side in the figure) of the valve housing side threaded portion 38b. The O-ring 39 is preliminarily mounted in the annular groove 39a, and is compressed and deformed when the plug member 35 is inserted into the assembling space 40 to seal the gap between the valve housing portion 37a and the plug member 35.

According to the structure of the above-described embodiment, since the O-ring 39 is provided inside the valve housing side screw portion 38b, when the plug member 35 is inserted into the valve housing portion 37a, the O-ring 39 is inserted. Since the ring 39 does not come into contact with the plug member side threaded portion 38a, there is no risk of damaging the O-ring 39 by the threaded portion 38a. Further, a taper portion 41 is formed at the outer peripheral portion of the plug member 35 and at the inner end portion of the surface facing the O-ring 39. When the plug member 35 is inserted, the O-ring 39 is gradually expanded and deformed while sliding on the surface of the tapered portion 41, so that the plug member 35 can be easily inserted and the O-ring 39 is prevented from being damaged.

Next, another embodiment of the present invention will be described with reference to FIG. FIG. 5 shows an embodiment in which the present invention is applied to a power cylinder of a rack and pinion type power steering apparatus.

Reference numeral 50 denotes a cylinder tube in the power cylinder of the rack and pinion type power steering apparatus, which constitutes the container in the present invention. This cylinder tube 5
Cylinder tube side threaded portion 51
b is formed. Reference numeral 52 denotes an end cover, which constitutes a lid member in the present invention, and an end cover side screw portion 51a formed on the outer peripheral surface of the end cover 52 is screwed with a cylinder tube side screw portion 51b. The cylinder tube side threaded portion 51b and the end cover side threaded portion 51a form the threaded portion 51 in the present invention. The bush 5 is provided on the inner peripheral portion of the end cover 52.
3 is press-fitted and held, and this bush 53 slidably holds a rod 54 on its inner peripheral portion. Reference numeral 55 is a seal member held on the inner peripheral portion of the end cover 52, and seals the hydraulic oil leaking from the bush 53 and the rod 54. 56 is a piston fixed to the rod 54, and the piston 56 allows the cylinder tube 50
The hydraulic chamber formed between the rod 54 and the rod 54 is divided into left and right. Then, the pressure oil is supplied to and discharged from the left and right hydraulic chambers from a hydraulic pressure supply path (not shown), whereby the rod 54
Moves to the left and right to generate steering assist force.

Reference numeral 57 denotes an outer peripheral portion of the end cover 52, which is an O-ring provided in an annular groove 57a formed outside (on the left side in the drawing) of the end cover side screw portion 51a, and is an annular seal in the present invention. It constitutes a member.
This O-ring 57 is compressed and deformed when it is inserted into the cylinder tube 50 together with the end cover 52,
A seal is provided between the cylinder tube 50 and the end cover 52.

According to the structure of the above-described embodiment, since the O-ring 57 is provided outside the threaded portion 51, when the end cover 52 is inserted into the cylinder tube 50, the O-ring 57 is inserted into the cylinder. Tube side thread 5
Since there is no contact with the 1b, there is no risk of damaging the O-ring 57 by the threaded portion 51b.

The sealing device according to the present invention is not limited to the above-described embodiment, but is widely applicable to all sealing devices within the scope of the claims.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a rack and pinion type power steering apparatus showing an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part of FIG.

FIG. 3 is an enlarged view of a plug member 25 in FIG.

FIG. 4 is a sectional view of a rack and pinion type power steering apparatus showing another embodiment of the present invention.

FIG. 5 is a cross-sectional view of a power cylinder of a rack and pinion type power steering apparatus showing another embodiment of the present invention.

[Explanation of symbols]

1 Power steering body 2 stub shaft 2a Coupling serration part 2b dowel pin 3 pinion shaft 3a pinion teeth 4 torsion bar 5 racks 5a rack teeth 6 Safety spline section 7 Steering body 7a Valve housing part 7b Gear housing part 7c opening 8 built-in space 10 Rotary type flow path switching valve 11 rotor 11a outer peripheral surface 12 sleeves 12a inner peripheral surface 12c small diameter part 13a, 13b, 14a, 14b Valve groove 15 inlet port 16 outlet ports 17a Left output port 17b right output port 21 ball bearing 21a Step 22 Bush 25 plug members 26 Oil seal 27 Oil seal 28 Thread 28a Plug member side screw part 28b Valve housing side thread 29 O-ring 29a annular groove 30 taper 31 Mating hole 35 Plug member 37a Valve housing part 38a Plug member side screw part 38b Thread part on valve housing side 39 O-ring 39a annular groove 40 built-in space 41 Tapered part 50 cylinder tube 51 screw part 51a End cover side thread 51b Cylinder tube side thread 52 End cover 53 bush 54 rod 56 pistons 57 O-ring 57a annular groove CL left ventricle CR right room

Claims (5)

[Claims] 1. A container that contains a liquid and has an opening, a lid member that closes the opening and is attached from the outside of the container, and the lid member is attached to the opening of the container. In the state, a threaded portion formed on the outer peripheral portion of the lid member and the inner peripheral portion of the opening, which are the surfaces facing each other, and the lid member being the surface facing the both, A sealing device having an annular groove that is provided on one of the outer peripheral portion and the inner peripheral portion of the opening, and accommodates an annular seal member, wherein the screw portion and the annular groove are the opening portion where the lid member is the opening portion. The annular seal member housed in the annular groove is in a positional relationship where it does not interfere with a screw portion provided on the other of the outer peripheral portion of the lid member and the inner peripheral portion of the opening portion when mounted on the other. And seal device. 2. The sealing device according to claim 1, wherein the annular groove and the annular sealing member are provided on an outer peripheral portion of the lid member and outside a screw portion of the lid member. 3. A surface which is provided on either the outer peripheral portion of the lid member or the inner peripheral portion of the opening portion and which intersects with the annular seal member when the lid member is attached to the opening portion of the container. The sealing device according to claim 1 or 2, wherein a tapered surface is formed. 4. A fitting portion which is provided on an outer end surface of the lid member and which is fitted with a lid member mounting tool for screwing the lid member into the container. The sealing device according to any one of the above. 5. The container is a valve housing of a control valve for a power steering device, which switches oil supply oil passages to a power cylinder by rotation of a steering shaft, and the lid member is a plug screwed to the valve housing. It is a member, The sealing device as described in any one of Claims 1-4.