JP2000265813A - Valve timing adjusting device for automotive engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a valve timing adjusting device which can reduce weight, a manufacturing cost, improve assembling performance, and stabilize seal fastening margin against temperature. SOLUTION: Each vane 1b of a rotor-like vane member 1 is housed in each hydraulic chamber 3 prepared by partitioning respective shoes 10 of a housing 4, in a relatively rotatable manner. A rotation transmitting member 5 is formed independently on the housing 4 and connected thereto. The housing 4 is made of a synthetic resin. A seal 11 is integrated with the shoe 10 of the synthetic resin housing 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve timing adjusting device for changing the opening / closing timing of an intake valve or an exhaust valve of an automobile engine according to the driving situation.

[0002]

2. Description of the Related Art This type of valve timing apparatus is provided in a drive transmission system between a crankshaft of an engine and a camshaft for driving an intake valve or an exhaust valve, and includes a vane rotor coupled to the camshaft, and a crankshaft. And a shoe housing to which rotation is transmitted from a shaft. The vane rotor is housed in the housing so as to be relatively rotatable within a predetermined rotation angle, and the phase difference of the vane rotor with respect to the housing is controlled by pressure oil supplied into the housing. As such a valve timing device, the shoe housing is made of aluminum-based light alloy or iron-based metal,
A proposal has been made to reduce leakage of pressurized oil by a minimum necessary clearance formed between the vane rotor and the shoe housing. Further, in order to prevent leakage of pressure oil from a gap between the vane rotor and the shoe housing, a leaf spring and a resin sealing material are mounted on the vane rotor and the shoe housing as a set.

[0003]

However, the valve timing device having the above configuration has the following problems. Constructing the shoe housing having the largest volume in the valve timing device with a light alloy or an iron-based metal goes against weight reduction. For this reason, the weight of the entire apparatus is inevitably increased, and the manufacturing cost is increased. From the viewpoints of fuel efficiency, environmental conservation, cost reduction, and the like, automobile parts are required to be slightly reduced in weight and cost, and it is difficult to sufficiently meet such demands. Managing the leakage of pressurized oil by the gap between the vane rotor and the shoe housing requires strict control of the individual dimensional accuracy of each component, and requires time-consuming work such as selective fitting during assembly. Is done. Due to the difference in the material of the resin seal and the shoe housing mounted on the tip of the vane rotor, the difference in linear expansion coefficient is large, and the interference of the seal changes due to heat, which has an adverse effect. Further, since the leaf spring and the seal member are mounted on the vane rotor and the shoe housing as a set, assembly of the apparatus is not easy.

It is an object of the present invention to provide a valve timing adjusting device for an automobile engine which can reduce the weight and cost and stabilize the temperature of the sealing margin. Another object of the present invention is to make the housing made of resin,
An object is to improve strength and sliding characteristics and to suppress thermal expansion. Still another object of the present invention is to improve assemblability without lowering sealing performance.
Still another object of the present invention is to improve the moldability of the housing while ensuring the sealing performance.

[0005]

The valve timing adjusting apparatus for an automobile engine according to the present invention is based on the premise that a vane member and a hydraulic chamber accommodating the vane member so as to be relatively rotatable within a predetermined angle range are described. A formed housing, a rotation transmitting member formed separately from the housing and coupled to the housing, and a hydraulic fluid supplied to and discharged from the hydraulic pressure chamber to adjust a phase difference between the vane member and the housing. Liquid path. The valve timing device is provided between a crankshaft of an automobile engine and a camshaft that drives at least one of an intake valve and an exhaust valve of the engine. The rotation transmitting member transmits the rotation, and the vane rotates together with the other shaft. The present invention is characterized in that, in the valve timing adjusting device having the above configuration, at least the peripheral wall of the housing is made of a heat-resistant synthetic resin. As described above, since the peripheral wall portion of the housing, which is the largest component among the components, is made of synthetic resin, the weight of the entire apparatus is reduced and the manufacturing cost is reduced. In addition, since the peripheral wall of the housing is made of synthetic resin, the difference in linear expansion coefficient between the seal attached to the vane member and generally made of resin and the peripheral wall of the housing is reduced, and the change in seal interference due to heat is reduced. Is unlikely to occur. Therefore, stable sealing performance can be obtained even when the temperature change is large. Since the housing is formed separately from the rotation transmitting member, only the rotation transmitting member can be made rigid for transmitting rotation by meshing or the like.

In the present invention, the housing includes a housing main body serving as a peripheral wall portion and a pair of side wall materials serving as side wall portions, and the pair of side wall materials are joined to both side surfaces of the housing main body. May be. By configuring the housing with three members in this manner, the shape of each member is simplified and manufacturing is facilitated, and for each housing component, an optimal material according to the required function can be selected. it can.

In the present invention, the peripheral wall of the housing may be made of a polyamide resin. The polyamide resin has a function as a heat-resistant synthetic resin and is inexpensive, so that the cost of the valve timing adjusting device can be further reduced. The polyamide resin may be a mixture of 6-nylon and 15% or less of carbon fiber. By incorporating carbon fibers, which are reinforcing fibers, the strength of the housing can be increased, the sliding characteristics can be improved, expansion due to heat can be suppressed, and the liquid tightness of the hydraulic chamber can be easily ensured. It is preferable that the amount of carbon fiber is large to some extent from the viewpoint of strength and the like. However, if it is more than 15%, the moldability decreases and the cost increases.

In the present invention, the seal contacting the vane member may be formed integrally with the housing made of a heat-resistant synthetic resin. Since the peripheral wall of the housing is made of a heat-resistant synthetic resin, the seal can be integrally formed in this manner. By forming the seal integrally with the housing in this way, the step of incorporating the seal and the spring member for backing up the seal is omitted, and the assemblability is facilitated.
The number of parts is small, and parts management becomes easy.

In the case where the peripheral wall of the housing has shoes at a plurality of locations on the inner peripheral surface in the circumferential direction, the seals are used to partition the hydraulic chambers from each other. It may be formed of lip portions which are formed on both edges in the direction along the axial direction and are bifurcated with each other. These lip portions are brought into sliding contact with the outer diameter surface of the boss portion of the vane member. As described above, by forming the seal as a bifurcated lip, a good sealing function can be secured against rotation of the vane member in both the forward and reverse directions, and the contact force with the vane member is also constant. Further, since these lips are formed at the tip of the shoe along the axial direction, the mold can be removed in the axial direction when integrally forming the lip serving as a seal on the peripheral wall of the housing. For this reason, the tip of the lip can be easily formed into a free cross-sectional shape such as, for example, an arc-shaped cross section, and a seal tip having excellent sealing performance and sliding characteristics can be obtained.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIG. The valve timing adjusting device for an automobile engine includes a housing 4 having a vane member 1, a hydraulic chamber 3 accommodating the vane member 1 so as to be rotatable within a predetermined angle range, and a housing 4 formed separately from the housing 4. And a rotation transmitting member 5 coupled to the housing 4. Liquid passages 21 and 22 for supplying and discharging hydraulic fluid such as oil to adjust the phase difference of the vane member 1 with respect to the housing 4 are provided for each hydraulic pressure chamber 3. Further, a rotation lock mechanism 15 for locking relative rotation is provided between the vane member 1 and the housing 4.

The vane member 1 is composed of a vane rotor having a plurality (four in the illustrated example) of vanes 1b provided on the outer periphery of a boss portion 1a, and is fixedly connected to a tip end of a cam shaft 6 by a coupling member 7 such as a bolt. Have been. The camshaft 6 is for opening and closing both or one of an intake valve and an exhaust valve (not shown) of the automobile engine.

The rotation transmitting member 5 is a ring-shaped member that is rotationally transmitted from a crankshaft (not shown) of the engine via a transmission mechanism (not shown) such as a gear train, and has a gear portion 5a on its outer periphery. Have. The rotation transmitting member 5 is made of metal such as iron. The rotation transmitting member 5 is rotatably fitted to a fitting shaft 6a at the tip of the camshaft 6, and one width surface is engaged with a flange 6b provided adjacent to the fitting shaft 6a. . The rotation transmitting member 5 and the housing 4
It rotates clockwise as viewed from the direction of arrow X in FIG.
This rotation direction is referred to as an advance direction a.

The housing 4 includes a housing main body 4a serving as a peripheral wall and a pair of side wall members 4b and 4c serving as side walls. Each of the side wall members 4b and 4c is a disk-shaped member having a central hole. The outer diameter portions are overlapped on both side surfaces of the housing main body 4a, and are connected to the housing main body 4a by the connecting members 8. The coupling tool 8 also serves as a means for coupling the housing 4 and the rotation transmitting member 5, and includes a housing body 4a,
The four members of the side wall members 4b and 4c and the rotation transmitting member 5 are integrally joined in a fixed state. The coupling member 8 is composed of a bolt, is inserted into a bolt insertion hole 9 provided in the housing 4 over each of the constituent members 4 a to 4 c, and has a distal end screwed into a screw hole of the rotating member 5. The bolt insertion hole 9 is provided in each shoe 10 of the housing 4 described later. The outer diameter of the housing 4 may be larger or smaller than the outer diameter of the rotation transmitting member 5, but in this example, it is formed substantially equal to the outer diameter of the rotation transmitting member 5. The inner wall surface of the side wall member 4 c of the housing 4 on the rotation transmitting member 5 side is rotatably fitted to the fitting shaft portion 6 a of the camshaft 6. Also,
The side surface of the side wall member 4c on the outer side of the housing is formed as a stepped surface protruding from the center portion side, and is fitted with the side surface of the rotation transmitting member 5 which is a stepped surface.

The housing 4 comprises a shoe housing in which a plurality of shoes 10 are formed on the inner periphery of a housing main body 4a serving as a peripheral wall, and a fan-shaped space formed between adjacent shoes 10 is provided with each vane 1b. Is the above-mentioned hydraulic chamber 3 for accommodating the pressure. The angle at which the vane 1 b can rotate within the hydraulic pressure chamber 3 is a predetermined angle range in which the vane member 1 can rotate relative to the housing 4. The inner diameter of the side wall members 4b and 4c serving as both side walls of the housing 4 is smaller than the tip position of the shoe 10, and the boss portion 1a of the vane member 1 is formed.
Are in contact with the inner surfaces of the housing side wall members 4b and 4c, and each hydraulic chamber 3 is a closed space. Each of the hydraulic chambers 3 is partitioned by a vane 1b, and the hydraulic chamber portion behind the vane 1b in the advancing angle direction a is a retard hydraulic chamber 3a, and the hydraulic chamber portion in the forward direction is an advancing hydraulic fluid. The pressure chamber 3b.

A housing main body 4a, which is a peripheral wall of the housing 4, is made of a heat-resistant synthetic resin, and a seal 11 which is in sliding contact with the outer diameter surface of the boss 1a of the vane member 1 is integrally formed. The seal 11 is composed of lip portions 11a, 11a that are bifurcated from each other and are formed along the axial direction at both ends in the circumferential direction of the housing at the tip of each shoe 10. These lip portions 11a, 11a are spread in an inverted V-shape with each other, and the cross-sectional shape of the tip is formed in an arc shape so as to be in close contact with the boss portion 1a of the vane member 1. The space between both lip portions 11a and 11b at the tip of each shoe 10 serves as a holding portion for the hydraulic fluid. The material of the side wall members 4b and 4c of the housing 4 may be a metal material such as a lightweight alloy, or may be made of a heat-resistant synthetic resin similarly to the housing body 4a.

As the heat-resistant synthetic resin constituting the housing 4, a polyamide resin (for example, 6-nylon, 6.
6-nylon, 4.6-nylon, 1.1-nylon,
1.2-nylon or 6.12 nylon), polyphenylene sulfide resin, polybutylene terephthalate resin, polyether sulfide resin, polyether ether ketone resin, polyamideimide resin, polyite resin, phenol resin, or the like is used. As additives, glass fiber, carbon fiber, calcium titanate,
Talc or calcium carbonate is used. Of these, a polyamide resin obtained by blending carbon fiber with 6-nylon at about 15% is preferable.

The tip end surface of each vane 1b of the vane member 1 is formed in a cylindrical shape, and fits into the inner diameter surface of the housing 4 via a small gap that can be relatively rotated. A seal groove 12 extending in the axial direction is provided on the distal end surface of each vane 1b, and a seal 13 made of resin or the like that is in close contact with the inner diameter surface of the housing 4 is fitted.

The oil passages 21 and 22 communicating with the respective hydraulic chambers 3 will be described. Each of the retard hydraulic chambers 3 a is connected via a first oil passage 21 to a hydraulic pressure source or a drain, which is a driving unit (not shown). Each advance angle hydraulic chamber 3b is connected via a second oil passage 22 to a hydraulic pressure source or drain, which is a drive unit (not shown). The first and second oil passages 21 and 22 communicate with each other over the vane member 1 and the camshaft 6, and the entrances 21 a and 22 a provided on the camshaft 6 are provided.
From the hydraulic pressure source.

The rotation lock mechanism 15 is means for locking the relative rotation of the vane member 1 with respect to the housing 4 when the vane member 1 is at the most retarded position with respect to the housing 4. Locking and unlocking operations are performed in response to pressure. The rotation lock mechanism 15 includes, for example, a stopper piston 17 slidable in an axial hole 19 provided in the vane member 1.
And a stopper hole 16 provided in the housing 4 and engaged with a stopper piston 17.
And a hydraulic chamber (not shown) provided on the vane member 1 to apply hydraulic pressure to the stopper piston 17. The hydraulic chamber communicates with the first or second liquid passages 21 and 22. It is assumed.

Next, the operation of the above configuration will be described. During normal operation of the engine, hydraulic fluid such as pressure oil is supplied to the retard hydraulic chamber 3a and the advance hydraulic chamber 3b. The rotation lock mechanism 15 in the vane member 1 is configured such that the stopper piston 17 comes out of the engagement hole 16 of the housing 4 due to the hydraulic pressure supplied to the hydraulic chambers 3a and 3b. Can rotate freely. Therefore, by controlling the hydraulic pressure applied to each of the hydraulic chambers 3a and 3b, the phase difference of the camshaft 6 with respect to the crankshaft is adjusted. When the engine stops, the retard hydraulic chamber 3
Since the hydraulic fluid is not supplied to the a and the advance hydraulic chamber 3b, the vane member 1 stops at the most retarded position with respect to the housing 4 (the state of FIG. 1B). At this time, since the hydraulic fluid is not supplied to the rotation lock mechanism 15, the stopper piston 17 is engaged with the stopper hole 16 by the urging force of the engagement urging spring 18. Even when the engine is restarted, the stopper piston 17 remains engaged with the stopper hole 16 until the hydraulic fluid is supplied to the retard hydraulic chamber 3a and the advance hydraulic chamber 3b. Thus, the camshaft 6 is held at the most retarded position. When the hydraulic fluid is supplied to each of the hydraulic chambers 3a and 3b, the stopper piston 17 of the rotation lock mechanism 15 comes out of the stopper hole 16 against the engagement urging spring 18 due to the hydraulic pressure. As a result, the engagement between the housing 4 and the vane member 1 by the rotation lock mechanism 15 is released, so that the operating fluid pressure applied to the retard hydraulic chamber 3a and the advance hydraulic chamber 3b causes the vane to move relative to the housing 4. The member 1 rotates relatively, and the relative phase difference between the camshaft and the crankshaft is adjusted.

According to the valve timing adjusting apparatus of this configuration, the housing body 4a of the housing 4, which is the largest component among the components, is made of synthetic resin.
Significant weight reduction can be achieved as compared with iron-based sintered alloys and the like, and the manufacturing cost is reduced. Since the housing 4 is formed separately from the rotation transmitting member 5, only the rotation transmitting member 5 can be made rigid for transmitting rotation by meshing or the like. In addition, since the housing 4 is made of synthetic resin and the seal lip portion 11a is formed integrally, it is possible to prevent the pressure liquid from leaking from the gap with the vane member 1.
Therefore, it is not necessary to use a combination of a sealing material and a leaf spring for backup as in the related art, and the assembly is simplified. Since the seal lip portion 11a is made of the same material as the housing 4, excellent sealing performance is obtained without being affected by a difference in thermal expansion due to a temperature change.

In the above-described embodiment, the housing 4 is constituted by the housing body 4a and the pair of side wall members 4b and 4c. However, the housing body 4a and one of the side wall members 4b are formed.
b, 4c and the other side wall member 4
b and 4c, and the entire housing 4 may be an integral member. In the above-described embodiment, the vane member 1 is made of metal. However, the vane member 1 can be made of a heat-resistant synthetic resin. In that case,
For example, as shown in FIG. 2, the seal 23 that slides on the inner diameter surface of the housing 4 can be formed integrally with the vane member 1. Further, in each of the above embodiments, the vane member 1 is connected to the camshaft 6 and the rotation transmitting member 5 is rotationally transmitted from the crankshaft. However, the vane member 1 is connected to the crankshaft via the rotation transmitting mechanism. Alternatively, the rotation transmitting member 5 may be connected to the camshaft via a rotation transmitting member such as a gear.

[0023]

According to the valve timing adjusting device for an automobile engine of the present invention, since at least the peripheral wall of the housing is made of a heat-resistant synthetic resin, the weight and cost can be reduced.
Temperature stabilization of the seal interference is also obtained. The housing is
When the housing body is a peripheral wall portion and a pair of side wall materials is formed as a side wall portion, and the pair of side wall materials are joined to both side surfaces of the housing body, manufacturing becomes easy, and each housing component Each time, an optimum material according to the required function can be selected. When the peripheral wall of the housing is made of a polyamide resin, the material cost is low and the cost can be further reduced. The polyamide resin is 6
-If carbon fiber is added to nylon at 15% or less, the strength of the housing can be increased, the sliding characteristics can be improved, expansion due to heat can be suppressed, and the liquid tightness of the hydraulic chamber can be improved. Easy to secure. In addition, it is possible to prevent a decrease in moldability due to the mixing of carbon fibers. If the seal that comes into contact with the vane member is formed integrally with the heat-resistant synthetic resin part of the housing, the step of incorporating the seal and its backup spring member is omitted, facilitating assembly and reducing the number of parts. Less parts management becomes easier. The peripheral wall portion of the housing has, at a plurality of locations on the inner peripheral surface in the circumferential direction, shoes that partition the respective hydraulic chambers from each other, and the seal is formed along the axial direction at both ends in the circumferential direction of the housing at the tip of the shoe. In the case where the lip portions are formed in a bifurcated shape, the sealing performance is ensured and the moldability of the housing is improved.

[Brief description of the drawings]

FIG. 1A is a cutaway front view of a valve timing adjustment device according to an embodiment of the present invention, and FIG. 1B is a cutaway side view of the valve timing adjustment device cut in a stepwise manner.

FIG. 2 is a cutaway side view of a valve timing adjusting device according to another embodiment of the present invention, which is cut in a stepwise manner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Vane member 1a ... Boss part 1b ... Vane 3 ... Hydraulic chamber 4 ... Housing 4a ... Housing body 4b, 4c ... Side wall member 5 ... Rotation transmission member 6 ... Camshaft 10 ... Shoe 11 ... Seal 11a ... Lip part 21, 22 ... oil passage

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yutaka Nanbu 1578 Higashikaizuka, Iwata-shi, Shizuoka Prefecture Inside NTN Co., Ltd. Terms (reference) 3G016 AA06 AA19 BA21 BA38 CA01 CA13 CA27 CA33 CA36 CA46 CA51 CA52 DA06 DA22 EA08 EA12 EA17 GA00 GA01

Claims (6)

[Claims] 1. A vane member, a housing having a hydraulic chamber for accommodating the vane member so as to be relatively rotatable within a predetermined angle range, and a rotation transmission formed separately from the housing and coupled to the housing. A member, and a fluid path for supplying and discharging hydraulic fluid to and from the hydraulic chamber to adjust a phase difference of the vane with respect to the housing, wherein both a crankshaft of an automobile engine and both an intake valve and an exhaust valve of the engine are provided. Or, an engine provided between a camshaft that drives one of the two shafts, wherein the rotation transmitting member transmits the rotation to one of the two shafts, and the vane member rotates together with the other shaft. A valve timing adjusting device for a vehicle, wherein at least a peripheral wall of the housing is made of a heat-resistant synthetic resin. Gin valve timing adjustment device. 2. The housing according to claim 1, wherein the housing comprises a housing main body serving as a peripheral wall portion and a pair of side wall materials serving as side wall portions, and the pair of side wall materials are joined to both side surfaces of the housing main body. Valve timing adjustment device for automobile engine. 3. The valve timing adjusting device for an automobile engine according to claim 1, wherein the peripheral wall of the housing is made of a polyamide resin. 4. The valve timing adjusting device for an automobile engine according to claim 3, wherein the polyamide resin is obtained by blending 15% or less of carbon fiber with 6-nylon. 5. The valve timing adjusting device for an automobile engine according to claim 1, wherein a seal contacting the vane member is formed integrally with the heat-resistant synthetic resin portion of the housing. . 6. A peripheral wall portion of the housing has, at a plurality of locations on an inner peripheral surface in a circumferential direction, shoes for partitioning the hydraulic chambers from each other, and the seal is provided at a tip end of the shoe in a circumferential direction of the housing. 6. The valve timing adjusting device for an automobile engine according to claim 5, further comprising a bifurcated lip formed on both edges along the axial direction, and the lips slidingly contacting the outer diameter surface of the boss of the vane member.