JPH0979011A - Valve opening/closing timing control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the work manhour of a tooth formed on a transmitting member by coupling an input member having outer tooth and an output member on which a cam for opening/closing a valve is formed and which have outer tooth, with a cylindrical transmitting member for changing both relative rotating positions by movement toward an axial direction. SOLUTION: A valve opening/closing period control device 10 is arranged on one end of a camshaft 21, in the case where it is judged that an engine is, for example, on a high speed and high load operation, a hydraulic converting valve is driven by a control device, oil pressure is fed to a spark-advance side oil pressure chamber 17, and it is acted to a piston 32. The inside of a delay angle side oil pressure chamber 16 is formed as cylinder head inner pressure, and thereby, the piston 32 is moved in a left direction so as to held the clearance between the piston 32 and the piston 31. At this time, connection of the helical spline 133 of a timing pulley 1 and helical splines 312, 323, 313, 324 of the piston 3, and the helical spline 223 of a camshaft member 2 is weakened so as to move the piston 3 in good responsiveness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve opening / closing timing control device.

[0002]

2. Description of the Related Art Conventionally, as a valve opening / closing timing control device of this type, for example, a device disclosed in Japanese Patent Publication No. 5-77843 is known. This is a camshaft that is an output member that has a cam that opens and closes a valve, a timing pulley that is an input member that is rotatably disposed around the camshaft and that receives power, a camshaft and timing. And a cylindrical piston arranged between the pulleys for transmitting torque between the pulleys and varying the relative rotational position of the cam shaft with respect to the timing pulley according to the position. Further, in this structure, helical outer teeth are formed on the outer circumference of the camshaft, helical inner teeth are formed on the inner circumference of the timing pulley, and the outer teeth of the camshaft are engaged with the inner circumference of the piston. The helical inner teeth are formed on the outer periphery thereof, and the outer helical teeth are formed on the outer periphery thereof to engage with the inner teeth of the timing pulley.

[0003]

However, since the piston is arranged between the cam shaft and the timing pulley in this case, it is necessary to form the inner teeth and the outer teeth on the inner and outer circumferences of the piston as described above. Yes, the processing man-hour increases.

Further, since the external teeth are formed on the outer circumference of the piston, the length from the axial center of the cam shaft to the external teeth (hereinafter referred to as the diameter of the external teeth) becomes large, which corresponds to the maximum amount of angle change. The locus length of the external tooth (that is, the arc length of the external tooth) increases. As a result, it is necessary to set a large stroke in the axial direction of the piston in order to set the maximum amount of change in angle to a desired amount. Therefore, the axial length of the entire device becomes long.

Therefore, according to the present invention, it is necessary to reduce the man-hours for processing the teeth formed on the transmission member (piston) and to reduce the tooth diameter of the transmission member to shorten the axial length of the entire apparatus. This is a technical issue.

[0006]

The first means taken in the present invention to solve the above technical problem is to provide an input member having external teeth to which power is input and a cam for opening and closing a valve on an axis. It transmits torque between the output member having external teeth and the both members and is movable in the axial direction, and changes the relative rotational position of the output member with respect to the input member according to the position. A cylindrical transmission member, wherein external teeth of the input and output members are arranged in the transmission member, and the transmission member has first internal teeth that engage with external teeth of the input member;
Forming a second inner tooth that engages an outer tooth of the output member,
At least one of the external teeth of the input member, the first internal teeth, the external teeth of the output member, and the second internal teeth is helical.

According to the above-mentioned first means, since the outer teeth of the input and output members are arranged in the transmission member, it is only necessary to form the inner teeth which engage with the respective outer teeth on the transmission member. It is not necessary to form both internal and external teeth. As a result, the number of man-hours for processing the teeth formed on the transmission member can be shortened.

Further, since only the inner teeth are formed on the transmission member, the tooth diameter can be made smaller than that in the case where both the inner teeth and the outer teeth are formed on the transmission member, which corresponds to the maximum variation amount. The length of the arc drawn by the teeth can be reduced. As a result, the stroke of the transmission member in the axial direction can be reduced without reducing the maximum variation (desired variation). Therefore, the axial length of the entire device can be shortened.

The second means taken in the present invention to solve the above technical problems is, in addition to the above first means,
Outer teeth of the input and output members are arranged on the same circumference centered on the shaft, and extend between the outer teeth along the circumference and the output member with respect to the input member. Is to provide a void having a length equal to or greater than the maximum amount of displacement when rotating relative to each other.

According to the second means, since the outer teeth of the input and output members are arranged on the same circumference with the axis of the output member as the center, the tooth diameter of the inner teeth of the transmission member can be further reduced, The stroke of the transmission member in the axial direction can be further reduced. Therefore, the axial length of the entire device can be further shortened.

Further, a gap having a length equal to or larger than the maximum variation amount when the output member relatively rotates with respect to the input member is provided between the outer teeth because the gap extends along the circumference. The output member can surely rotate relative to the input member up to the maximum variation amount.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

The valve opening / closing timing control device 10 of the first embodiment will be described with reference to FIGS.

In FIG. 1, the valve opening / closing timing control device 10 has a maximum retarded state in the upper half with a horizontal center line X as a boundary.
The lower half shows the maximum advance state. The valve opening / closing timing control device 10 is attached to one end of a cam shaft 21 as shown in FIG. 5, and has a timing pulley (input member) 1, a cam shaft member (output member) 2, and a piston (transmission member).
3 is provided.

The timing pulley 1 includes a gear portion 11, a cylindrical cover 12 having a bottom, and a spline member 13, and a chamber 14 is formed therein. As shown in FIG.
The gear portion 11 is connected to the crank pulley 51 of the engine 55 via the timing belt 52 and takes in the rotational power of the crank pulley 51. The cover 12 covers the left end of the camshaft 21 and the bolt 1 on the gear portion 11.
5 fixed.

The spline member 13 is fixed to the gear portion 11 and is supported around the cam shaft 21 so as to be rotatable relative thereto. Therefore, the timing pulley 1 is rotatable relative to the cam shaft 21. As shown in FIG.
The spline member 13 includes a cylindrical main body 131, two flange portions 132 and 132, and helical splines (external teeth) 133 and 133. Flange part 132
Protrude from the main body 131 in the axial direction of the camshaft 21 and face each other while being spaced apart from each other. Further, the flange portion 132 is arranged on the circumference of a predetermined radius centered on the axial center of the cam shaft 21, and has an arcuate cross section. The helical spline 133 is formed over the entire outer peripheral portion of each flange portion 132, and its orientation is the same as when viewed from the front. Here, as shown in FIG. 4, the length of each flange portion 132 with the helical spline 133 is set to the length of a fan-shaped arc having an elevation angle of 70 °. The flange portion 13
The number of 2 may be 1 or 3 or more.

As shown in FIG. 1, the camshaft member 2
Includes a camshaft 21 and a spline member 22. As shown in FIG. 5, a plurality of cams 53 corresponding to the number of cylinders of the engine 55 are arranged around the camshaft 21, and at least intake valves 54 (four intake valves in FIG. 5) of intake and exhaust valves of the engine 55 are arranged. Only one intake valve of the valves is shown) opened and closed.

Returning to FIG. 1, the spline member 22 is fixed to the left end of the camshaft 21 by a bolt 23, and cannot be rotated relative to the camshaft 21 by the action of the pin 24. As shown in FIG. 2, the spline member 22 includes a disc-shaped main body 221 and two flange portions 22.
2, 222 and helical spline (external teeth) 223, 2
23. The flange portion 222 has one end fixed to the outer peripheral portion of the main body 221, extends in the axial direction of the cam shaft 21, and is opposed to and spaced from each other. The flange portions 222 are alternately arranged on the same circumference as the flange portions 132 of the spline member 13 and have an arcuate cross section. The helical spline 223 is formed over the entire outer peripheral portion of each flange portion 222, the direction thereof is the same as viewed from the front, and the helical spline 133 intersects the helical spline 133 in an opposite direction. Here, as shown in FIG. 4, the length of each flange portion 222 with the helical spline 223 is the same as that of the flange portion 132, and the elevation angle is 70 °.
It is set to the length of a fan-shaped arc.

As shown in FIG. 4, both flange portions 132,
A space 40 is provided between the two 222, which is located on the same circumference as the two and extends along the circumference. Void 4
The length of 0 is an arc corresponding to the maximum variation amount (here, set to 30 °) when the camshaft member 2 relatively rotates with respect to the timing pulley 1 at the maximum retard angle (or at the maximum advance angle). Is set longer than the length of. Here, the length of the gap 40 is set to the length of a fan-shaped arc having an elevation angle of 40 ° at the maximum retard angle (or at the maximum advance angle).

Returning to FIG. 1, the cylindrical piston 3 is axially slidably arranged on the outer circumference of the spline members 13 and 22 in the chamber 14. The piston 3 includes a first piston 31 and a second piston 32 that are divided into two in the axial direction, and a spring 33 that biases the pistons 31 and 32 in a direction in which they are separated from each other.

The first piston 31 has a cylindrical body 311.
And two first helical splines (first internal teeth) 31
2, 312 and two second helical splines (second internal teeth) 313, 313. As shown in FIG. 3, the first helical splines 312 are formed on the inner peripheral portion of the main body 311, and are spaced apart from each other and face each other. Each of the first helical splines 312 corresponds to the timing pulley 1
Are engaged with the respective helical splines 133, and the orientation thereof corresponds to that of the helical splines 133. On the other hand, the second helical spline 313 is
It is formed so as to be located between the first helical splines 312 on the inner peripheral portion of the first No. 1, and is opposed to each other with a space therebetween. Each of the second helical splines 313 engages with each of the helical splines 223 of the camshaft member 2, and its orientation corresponds to that of the helical splines 223.

The second piston 32 has a cylindrical first main body 321 and a second main body 322 which are divided into two in the axial direction, and two first helical splines (first internal teeth) 323, 32.
3 and two second helical splines (second internal teeth) 3
24, 324. As shown in FIG.
The second main bodies 321 and 322 are fixed to each other.
The first helical splines 323 are formed on the inner peripheral portion of the first body 321 at positions corresponding to the first helical splines 312, and are spaced apart from each other and face each other. Each of the first helical splines 323 engages with each of the helical splines 133 of the timing pulley 1, and the orientation thereof corresponds to that of the helical splines 133. On the other hand, the second helical spline 324 includes the first main body 321.
Are formed so as to be located between the first helical splines 323 on the inner peripheral portion of the, and are opposed to each other at a position corresponding to the second helical splines 313 with being separated from each other. This each second
The helical splines 324 are engaged with the respective helical splines 223 of the camshaft member 2, and the orientations thereof are in a shape corresponding to the helical splines 223.
The first and second main bodies 321 and 322 may be integrally provided.

The spring 33 is arranged between the main body 311 of the first piston 31 and the second main body 322 of the second piston 32. The outer peripheral edge 322a of the second main body 322 is in liquid-tight contact with the inner peripheral surface of the cover 12 via the seal member 34, and the chamber 14 is divided into the retard side hydraulic chamber 16 and the advance side hydraulic chamber 17. It is partitioned. The piston 3 is slidable in the axial direction on the helical splines 133 and 223, but the sliding range thereof is the second main body 32 of the second piston 32 when advancing.
The left end surface of the outer peripheral edge 322 a of the cover 2 is the step portion 12 of the cover 12.
a until it comes into contact with a (the lower half of FIG. 1) or until the right end surface of the outer peripheral edge 322a of the second main body 322 comes into contact with the end 11a of the gear portion 11 (the upper half of FIG. 1) when retarded. is there. As the piston 3 moves in the axial direction, the helical spline 133 of the timing pulley 1 rotates clockwise and the helical spline 223 of the camshaft member 2 rotates counterclockwise from the state of FIG. 4 (maximum retarded state).

Since the first and second pistons 31 and 32 are urged by the spring 33 in directions away from each other,
From the state where the two pistons 31, 32 are in contact with each other, the first piston 31 is on the left side in FIG. 1, and the second piston 32 is on the left side in FIG.
Move to the right. That is, the spring 36 exerts an expanding action on the piston 3. Therefore, the first helical splines 312 and 323 of the piston 3 are aligned with the second helical splines 133 of the timing pulley 1 and the second helical splines 133 of the piston 3.
The helical splines 313 and 324 are pressed against the helical splines 223 of the camshaft member 2, respectively. That is, fill the backlash. Since these pressure contact forces act as sliding resistance when the piston 3 moves, it is also useful for stopping the piston 3 at that position.

A hydraulic circuit 61 shown in FIG. 6 supplies operating hydraulic pressure to the valve opening / closing timing control device 10. Here, the pump 63 draws oil from the oil pan 62 to generate hydraulic pressure,
The hydraulic pressure switching valve 64 supplies hydraulic pressure to one of the ports 65 and 66 provided in the camshaft 21. 67
Is a drain circuit. The hydraulic pressure switching valve 64 is driven by the control device 68, and the control device 68 outputs an optimum drive signal to the hydraulic pressure switching valve 64 according to various signals such as an engine load signal, a cam angle signal, and a crank angle signal that are input. .

In FIG. 1, the ports 65 and 66 are formed in a ring shape on the outer circumference of the camshaft 21. The port 65 communicates with one end of a passage 71 that extends in the axial direction inside the camshaft 21, and the passage 71 communicates with the advance side hydraulic chamber 17 via a passage 72 formed in the spline member 13 on the other side. ing. The left end of the passage 71 is closed by the spline member 22. The port 66 communicates the inner center of the camshaft 21 with one end of a passage 73 extending in the axial direction, and further communicates the inner center of the bolt 23 with the retard angle hydraulic chamber 16 via a passage 74 extending in the axial direction. ing.

The operation of the valve opening / closing timing control device 10 having the above construction will be described below.

As the engine 55 is started, the piston 3 immediately moves to the maximum retarded position shown in the upper half of FIG. This is the timing pulley 1 with which the piston 3 engages
The helical spline 133 and the helical spline 223 of the camshaft member 2 are inclined relative to the rotation direction of the timing pulley 1 so as to move the piston 3 to the maximum retarded position. is there. The force in this direction is always applied to the piston 3 during engine operation.
Continue to work on. By the time the pump 63 starts to generate hydraulic pressure, the hydraulic pressure switching valve 64 is initially in the OFF state and is held at the position for supplying hydraulic pressure to the port 66. It is filled with hydraulic pressure and the maximum retarded state is maintained. At this time, since the hydraulic pressure switching valve 64 communicates the port 65 with the drain circuit 67, the inside of the advance side hydraulic chamber 17 becomes the cylinder head internal pressure (approximately atmospheric pressure).

In the state where the retard angle side hydraulic chamber 16 is filled with hydraulic pressure, this hydraulic pressure acts on the second piston 32 and causes the right end surface of the outer peripheral edge 322a of the second piston 32 to move to the body 13
Abutting against the end 13a of the. However, the first piston 31
With respect to the above, since the hydraulic pressure acts on both left and right end surfaces, the hydraulic pressure in the retard angle side hydraulic chamber 16 does not generate a force that moves the first piston 31 in the horizontal direction. Regardless of the maximum retarded state described above and the maximum advanced state described later, the engine 55
Of the crank pulley 51 and the timing belt 52 via the gear portion 11 of the timing pulley 1 and the spline member 1
The rotational power (torque) input to the first and second helical splines 3 of the pistons 31 and 32, which are engaged with the helical spline 133 of the spline member 13 in a pressure contact state.
12 and 323, and further both pistons 31, 32
Helical spline 22 of the spline member 22 that engages with the second helical splines 313, 324 in a pressed state.
3 is transmitted to the camshaft 21.

Here, the cam shaft 21 receives a variable torque from the cam system, and an extra rotational motion (such as a negative rotational motion) acts on the cam shaft 21 in addition to the original rotational motion of the cam shaft 21. Due to the expanding action of the spring 33, the helical spline 133 of the timing pulley 1 is
The first and second helical splines 31 of the piston 3
2, 323, 313, 324-Because the helical splines 223 of the camshaft member 2 are firmly connected to each other without any gaps, a tapping sound based on the gaps between the joints is not generated.

When the state of the engine 55 is judged by various signals inputted to the control device 68, for example, when it is judged that high speed / high load operation is being performed, the control device 68 drives the hydraulic pressure switching valve 64 to drive the port 65. Set the position to supply hydraulic pressure to. As a result, the hydraulic pressure is supplied to the advance side hydraulic chamber 17 and acts on the second piston 32. At the same time, since the port 66 communicates with the drain circuit 67 by the hydraulic pressure switching valve 64, the retard side hydraulic chamber 16 becomes the cylinder head internal pressure (approximately atmospheric pressure). At this time, since there is a gap between the first piston 31 and the second piston 32, the second piston 32 moves so as to narrow the gap with the first piston 31. That is, the spring 33 is slightly contracted, and the helical spline 133-of the timing pulley 1 due to the expansion action thereof.
The first and second helical splines 312 of the piston 3
323, 313, 324-The helical spline 223 of the camshaft member 2 is weakly coupled. Therefore, the sliding resistance when the piston 3 moves is reduced, and the piston 3 moves in the advance direction with good responsiveness. In other words, the piston 3 moves to the left while reducing the biasing force of the spring 33 in the predetermined direction, and finally moves to the lower half position in FIG. The above action is exerted when the movement force acts on the piston 3 (when the hydraulic pressure in the advance side hydraulic chamber 17 is superior to the hydraulic pressure in the retard side hydraulic chamber 16).

However, at the position of maximum advance shown in the lower half of FIG. 1, the left end surface of the outer peripheral edge 322a of the second piston 32 contacts the stepped portion 12a of the cover 12, so that the second piston 32 receives the advance. The hydraulic pressure in the angular hydraulic chamber 17 does not act on the first piston 31 indirectly. Therefore, the expanding action of the spring 33 acts again, and the helical spline 133 of the timing pulley 13-the first and second pistons 3 of the piston 3 are actuated.
Helical Splines 312, 323, 313, 324-
The connection of the helical spline 223 of the camshaft member 2 becomes strong without a gap.

Depending on how to control the hydraulic pressure switching valve 64,
The piston 3 can be stopped at an arbitrary position (intermediate advance position) between the maximum advance position and the maximum retard position. This can be achieved by balancing the hydraulic pressure in the retard side hydraulic chamber 16 and the hydraulic pressure in the advance side hydraulic chamber 17 when the piston 3 reaches an arbitrary position. Therefore, the amount of advance angle can be set to any amount between zero and maximum. In this way, even when the piston 3 is stopped at an arbitrary position, as described above, the piston 3
Since no moving force acts on the spring 33, the expanding action of the spring 33 works effectively.

In the present embodiment, an example in which all four splines are helical has been described, but only the splines of the timing pulley 1 and the first spline of the piston 3 are helical, or the camshaft member 2 is of a helical shape. Only the spline and the second spline of the piston 3 may be helical.

In addition, the control device 68 is operated during high speed and high load operation.
In the above description, the case where the hydraulic pressure switching valve 64 is driven to supply the hydraulic pressure to the port 65 has been described, but there are other conditions for supplying the hydraulic pressure to the port 65, and it may be appropriately set by design.

Although an example of a belt driven timing pulley is shown as an input member, any power input means may be used, and for example, a chain driven timing gear or a pair of cam shafts may be meshed with each other. It may be one of the gears.

Further, although the example of the compression spring having the expanding action as the elastic member has been shown, a tension spring can be used as the elastic member, and in this case, the urging force in the tension direction is reduced when advancing. Therefore, it is necessary to arrange the advance side hydraulic chamber on the left side of the second piston.

As described above, in this embodiment, since the helical splines 133 and 223 of the timing pulley 1 and the camshaft member 2 are arranged inside the piston 3, each helical spline 13 is provided on the inner peripheral portion of the piston 3.
It is only necessary to form a helical spline that engages with 3, 223, and it is not necessary to form a helical spline on the inner and outer circumferences of the piston 3. As a result, the man-hours for processing the helical spline formed on the piston 3 can be shortened.

Further, since the spline is formed only on the inner peripheral portion of the piston 3, the spline diameter can be made smaller than that of the piston 3 having the spline formed on the inner and outer peripheral portions thereof, and the inner angle corresponding to the maximum variation amount can be obtained. The length of the arc drawn by the teeth can be reduced. As a result, the stroke of the piston 3 in the axial direction can be reduced without reducing the maximum variation (desired variation). Therefore, the axial length of the entire device can be shortened.

Further, since the timing pulley 1 and the helical splines 133 and 223 of the camshaft member 2 are arranged on the same circumference centered on the axial center of the camshaft 21, the spline diameter of the piston 3 can be further reduced, and the piston 3 The stroke in the axial direction of 3 can be further reduced. Therefore, the axial length of the entire device can be further shortened.

Further, between the flange portion 132 with the helical spline 133 of the timing pulley 1 and the flange portion 222 with the helical spline 223 of the camshaft member 2, the camshaft member 2 is provided with respect to the timing pulley 1 on the same circumference. Since the gap 40 that is longer than the length corresponding to the maximum amount of change in relative rotation is provided, the camshaft member 2 reliably rotates relative to the timing pulley 2 by the maximum amount of change (set to 30 °). In addition, both flanges 132 and 222 do not interfere with each other during rotation.

[0042]

According to the invention of claim 1, since the outer teeth of the input and output members are arranged in the transmission member, it is only necessary to form the inner teeth for engaging the respective outer teeth on the transmission member. It is not necessary to form both internal and external teeth on the member. as a result,
The number of man-hours for processing the teeth formed on the transmission member can be shortened.

Further, since only the internal teeth are formed on the transmission member, the tooth diameter can be made smaller than that in the case where both the internal teeth and the external teeth are formed on the transmission member. The length of the arc drawn by the teeth can be reduced. As a result, the stroke of the transmission member in the axial direction can be reduced without reducing the maximum variation (desired variation). Therefore, the axial length of the entire device can be shortened.

According to the invention of claim 2, since the outer teeth of the input and output members are arranged on the same circumference with the axis of the output member as a center, the tooth diameter of the inner teeth of the transmission member can be further reduced. The stroke of the transmission member in the axial direction can be further reduced. Therefore, the axial length of the entire device can be further shortened.

Further, since a gap extending between the outer teeth and having a length equal to or greater than the maximum amount of angle change when the output member relatively rotates with respect to the input member is provided. The output member can surely rotate relative to the input member up to the maximum variation amount.

[Brief description of drawings]

FIG. 1 is a sectional view of a valve opening / closing timing control device according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of two spline members, a cam shaft, and a bolt in FIG.

FIG. 3 is an exploded perspective view of the piston in FIG.

FIG. 4 is a cross-sectional view of main parts of two spline members.

FIG. 5 is a configuration diagram of an engine.

FIG. 6 is a configuration diagram of a hydraulic circuit.

[Explanation of symbols]

1 Timing Pulley (Input Member) 133 Helical Spline (External Teeth) 2 Camshaft Member (Output Member) 223 Helical Spline (External Teeth) 3 Piston (Transmission Member) 312, 323 1st Helical Spline (First Internal Teeth) 313 , 324 Second helical spline (second internal tooth) 10 Valve opening / closing timing control device

Claims (2)

[Claims] 1. An input member to which power is input and which has external teeth, and a cam which opens and closes a valve are disposed on a shaft, and an output member having external teeth, and torque transmission between the both members, and a shaft. A cylindrical transmission member that is movable in a direction and changes the relative rotational position of the output member with respect to the input member in accordance with the position, and external teeth of the input and output members within the transmission member. And forming on the transmission member first internal teeth that engage with the external teeth of the input member and second internal teeth that engage with the external teeth of the output member, A valve opening / closing timing control device in which at least one of an external tooth, the first internal tooth, an external tooth of the output member, and the second internal tooth is helical. 2. The outer teeth of the input and output members according to claim 1, arranged on the same circumference with the shaft as a center, and extending between the outer teeth along the circumference. Further, a valve opening / closing timing control device provided with a gap having a length equal to or larger than a maximum variation amount when the output member relatively rotates with respect to the input member.