JP3404724B2 - Method of manufacturing valve timing adjusting device for internal combustion engine - Google Patents

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 intake / exhaust valves of an internal combustion engine in accordance with operating conditions.

[0002]

2. Description of the Related Art As a valve timing adjusting device for an internal combustion engine, a control member composed of a plurality of arc gears having helical splines on at least one of inner and outer circumferences and a piston is axially moved by hydraulic pressure or spring force. By doing so, there is one in which the crankshaft side member and the camshaft side member are relatively rotated.

[0003]

The arc-shaped gear meshed between the crankshaft-side member and the camshaft-side member is attached to the piston so as to form an apparently one cylindrical gear, The crankshaft side member and the camshaft side member are engaged with each other. By the elastic force of the springs provided in the arc gears biasing the adjacent arc gears in opposite directions in the axial direction of the cam shaft, the positive and negative fluctuations of the cam shaft are caused by each arc gear. Absorb torque. This eliminates backlash between the spline on the outer circumference of the arc gear and the spline on the crankshaft side member, and between the spline on the inner circumference of the arc gear and the spline on the camshaft side member to generate rattling noise. Is suppressed.

The elastic force of the spring is determined in consideration of variations in the axial displacement of the arc gear during spline engagement and variations in manufacturing of the arc gear. For this reason,
By dividing one cylindrical gear along the plane that passes through its diameter and the cylinder axis and reassembling the divided multiple arc-shaped gears to the piston, the unevenness of the axial displacement of each arc-shaped gear is reduced. Therefore, it is preferable to reduce the variation in elastic force and stabilize the performance of the apparatus.

Due to the division of the cylindrical gear, one spline may be divided into two. For example, in FIG.
As shown in (A), when the divided portion of the cylindrical gear is viewed from the outer peripheral direction of the cylindrical gear, the external tooth helical splines of the arc gears 50, 54 are cut off by the cutting portions 545, 505. 542 and 50
It is divided into two. Further, as shown in FIG. 8B, when viewed from the inner peripheral direction of the cylindrical gear, the cutting portions 505, 5
The internal tooth helical splines of the arc gears 50 and 54 are divided by 45 into internal tooth helical splines 503 and 543. However, when the spline is divided in this way, burrs are generated on the tooth surfaces of the cutting portions 545 and 505 due to the cutting process. The burr on the tooth surface increases the friction on the tooth surface with the mating spline at the time of meshing with the spline, and may deteriorate the operation response when the control member moves in the axial direction. In addition, the wear of the spline tooth surface is promoted due to the increase in the friction of the tooth surface, the backlash increases and the axial variation between the arc gears increases, and the elastic force of the spring is insufficient and the rattling noise is suppressed. The effect decreases. Therefore, it is necessary to remove this burr, and there is a problem that the cost for the deburring work increases.

Further, there is a possibility that a spline having an extremely short tooth width is formed depending on the division position. For example, in FIG.
The external tooth helical splines 501 and 542 and the internal tooth helical spline 543 shown in FIG. When torque is transmitted by the arc gear when the engine is operating, the load may concentrate on the spline with a short tooth width, resulting in abnormal wear. Further, due to factors such as eccentricity of the control member and fluctuations in rotation, the distribution of the transmission torque may concentrate on the spline having a short tooth width, resulting in chipping or cracking of the teeth. The tooth fragments resulting from the chipping or cracking may enter the fitting portion or the sliding portion in the engine or the device, thereby increasing the operating load, and possibly causing the engine or the device to stop operating.

According to the present invention, when an arc gear is manufactured by dividing a cylindrical gear, the work for removing burrs generated at the time of division is facilitated to reduce the number of processing steps, and the durability and reliability of the arc gear are improved. An object of the present invention is to provide a method for manufacturing a valve timing adjusting device for an internal combustion engine, which has improved performance.

[0008]

In order to solve the above problems, a method of manufacturing a valve timing adjusting device for an internal combustion engine according to claim 1 of the present invention is directed to at least one of an intake valve and an exhaust valve of the internal combustion engine. A cam shaft side member including a cam shaft for driving a valve, a rotation transmission member fixed to the cam shaft and rotating integrally with the cam shaft, and a crank shaft rotating in synchronization with a crank shaft of an internal combustion engine. Side member, the cam shaft side member, and the crank shaft side member, at least one of the teeth provided on the inner and outer peripheries is a helical tooth, and the crank is generated by moving in the axial direction. A shaft-side member and a control member for rotating the cam shaft-side member relative to each other, wherein the control member has a cylindrical integrated gear formed by combining a plurality of gears having an arc-shaped cross section; Of arcuate section The car has its inner periphery or the outer periphery helical, the helical teeth of the circumferential end portion, an internal combustion engine which is provided continuously obliquely from one axial end to the other axial end
Of the control member in the valve timing adjusting device of
A manufacturing method, in which at least one of the inner and outer circumferences has a helical tooth.
The process of forming a cylindrical gear having
Cut along the plane that passes through and the cylinder axis.
Step of cutting the cylindrical gear so as not to cross the helical teeth
And a plurality of gears with the arc-shaped cross section obtained by cutting
And a cylindrical integrated gear.
By providing a missing tooth in a part of the
To cut the cylindrical gear so that it does not cross the teeth.
Characterize.

According to a second aspect of the present invention, there is provided a method of manufacturing a valve timing adjusting device for an internal combustion engine, comprising:
It is characterized in that only such helical teeth are omitted.

[0010]

[0011]

According to the method of manufacturing the valve timing adjusting device for the internal combustion engine of the present invention, when the arc gear is manufactured by dividing the cylindrical gear, the helical teeth of the divided portion are made to have a missing tooth. Alternatively, the pitch of the helical teeth is increased so that the cutting portions do not divide the helical teeth. As a result, burrs do not occur on the tooth surface during division, the deburring work is facilitated, and the processing cost is reduced.

Further, since the divided spline having a short tooth width does not occur, the load is not concentrated on the short spline to cause wear or crack, and the durability and the reliability of the arc gear are improved. is there.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIGS. 1 to 6 show a valve timing adjusting device for an internal combustion engine according to a first embodiment of the present invention.

As shown in FIG. 2, a cylindrical camshaft sleeve 4 is fixed to one end of the camshaft 1 by bolts 2 and pins 3 so as to rotate integrally with the camshaft 1. An external tooth helical spline 4 a is formed on a part of the outer peripheral wall of the camshaft sleeve 4. The sprocket sleeve 7 includes an outer cylinder having a small diameter portion 7d and a large diameter portion 7e, an annular flange portion 7c extending radially outward from the side opposite to the small diameter portion of the large diameter portion 7e, an inner cylinder 7b, and a small diameter portion. An annular portion 7f that extends radially inward from the side of the larger diameter portion of 7d and connects the outer cylinder and the inner cylinder 7b is integrally formed. Internal tooth helical splines 7a are formed on a part of the inner peripheral wall of the small diameter portion 7d. The internal tooth helical spline 7 a is formed to have a twist angle in the opposite direction to the external tooth helical spline 4 a of the camshaft sleeve 4. External tooth helical spline 4
One of the internal tooth helical spline 7a and the internal tooth helical spline 7a may be a linear spline parallel to the axial direction with a twist angle of zero.

The flange member 8 is formed of an annular portion 8a extending in the radial direction of the camshaft 1 and a cylindrical portion 8b extending in the axial direction of the camshaft 1 toward the rear end side of the camshaft 1. Rotational torque from a crankshaft (not shown) is transmitted to the timing pulley 5 by a timing belt (not shown). The annular portion 8a of the flange member 8 and the flange portion 7c of the sprocket sleeve 7 are attached to the timing pulley 5 with bolts 6. The outer surface 7g of the inner cylindrical portion 7b of the sprocket sleeve 7 is supported by the inner surface 4b of the camshaft sleeve 4 at one end of the crankshaft side member, and the timing pulley 5 is provided at the other end of the crankshaft side member. The inner surface 8c of the cylindrical portion 8b of the camshaft flange member 8 is supported by the outer surface 1c of the camshaft 1, so that the timing pulley 5 is supported by the camshaft 1 so as to be relatively rotatable.

A control member 9 for relatively rotating the timing pulley 5 and the camshaft 1 is provided between the camshaft sleeve 4 and the sprocket sleeve 7.
By alternately assembling the two arc-shaped gears 10 and the two arc-shaped gears 14 to the piston portion 13 of the control member 9 shown in FIG. 3, one cylindrical gear is apparently formed as an integrated gear. A ring-shaped groove is formed by arc-shaped grooves 10e and 14e at the upper ends of the arc-shaped gears 10 and 14, and the retainer ring 12 is housed in the ring-shaped groove.

The arc gears 10 and 14 are manufactured by dividing one cylindrical gear into four on the circumference. As shown in FIG. 1A, by providing a missing tooth between the adjacent external tooth helical splines 142 and 101 on both sides of the cut portions 145 and 105, that is, between the external tooth helical splines 141 and 142 and By making the space between the external tooth helical splines 142 and 101 wider than the space between 101 and 102, the splines are not divided by the cutting portions 145 and 105. Similarly, as shown in FIG. 1B, by providing a missing tooth between the adjacent internal tooth helical splines 104 and 143 on both sides of the cutting portions 105 and 145, that is, the internal tooth helical splines 103 and 104, respectively. The gap between the internal tooth helical splines 104 and 143 is wider than that between the gaps and between 143 and 144 so that the splines are not divided by the cutting portions 105 and 145.

By providing one missing tooth between the external tooth helical splines 142 and 101, the cutting portion 105,
At 145, the rightmost external tooth helical spline 142 of the arc gear 14 shown in FIG. 1A starts from the upper end 145a, and the leftmost external tooth helical spline 101 of the arc gear 10 shown in FIG. The distance between the external tooth helical splines 142 and 101 is set so as to end at the lower end 105b. Similarly, by providing one missing tooth between the internal tooth helical splines 104 and 143, the rightmost internal tooth helical spline 104 of the arc gear 10 shown in FIG. 1B starts from the upper end 105a, The spacing between the internal tooth helical splines 104 and 143 is set so that the leftmost internal tooth helical spline 143 of the arc gear 14 shown in FIG. 1B ends at the lower end 145b of the cutting portion 145.

As shown in FIGS. 4 and 5, the arc-shaped gears 10 and 14 pass through the retainer ring 12 and the through holes 10d,
The pins 11 inserted into 14d alternately assemble the piston parts 13. Pin 11 is piston part 1
It is press-fitted and fixed to No. 3 and a slight clearance is provided between the arc gears 10 and 14 in the axial direction and the rotational direction in order to absorb an error during assembly. Arc gear 1
Inner peripheral helical splines 10a and 14a are formed on the inner peripheral walls of Nos. 0 and 14, and outer peripheral helical splines 10b and 14b are formed on the outer peripheral walls.

Two spring holders 14c are formed on both sides of the through hole 14d of the arc gear 14 in the rotational direction, and a spring 15 is housed in the spring holder 14c below the retainer ring 12. The axial movement of the arc gear 14 is possible within the compression range of the spring 15. Due to the elastic force of the spring 15 whose one end is supported by the retainer ring 12, the arc gear 14 is pressed toward the piston 13.

The internal gear helical splines 10a, 14a of the arc gears 10, 14 are fitted with the external gear helical splines 4a of the camshaft sleeve 4, and the external gear helical splines 10b, 14b are formed by the internal gear helical splines 7a of the sprocket sleeve 7. Mate with. At this time, the arc gear 1
Numeral 4 is fitted into the arc gear 10 while being displaced by a minute distance in the axial direction and the radial direction of the camshaft 1 by the amount of absorbing the backlash. That is, the arc gear 10 and the arc gear 14
Are subjected to the elastic force of the spring 15 in mutually opposite directions with respect to the axial direction of the camshaft 1. Due to this elastic force, a torque for rotating the camshaft 1 relative to the timing pulley 5 in the retard direction by the arc gear 10 and a torque for rotating the camshaft 1 in the advance direction with respect to the timing pulley 5 by the arc gear 14 is applied. give. Therefore, the positive and negative fluctuating torques of the camshaft can be absorbed by the respective arcuate gears, and the rattling noise between the backlashes can be suppressed.

Due to the engagement between the splines, the rotation of the timing pulley 5 is transmitted to the camshaft 1 via the sprocket sleeve 7, the control member 9 and the camshaft sleeve 4. Between the camshaft sleeve 4 and the sprocket sleeve 7, the piston ring 18 and the piston 13 fitted in the groove 13b of the piston 13 are provided.
Advance side hydraulic chamber 19 partitioned by the sliding portion 13a of
And the retard side hydraulic chamber 20 is formed. The advance side hydraulic chamber 19 and the retard side hydraulic chamber 20 are liquid-sealed by the O-ring 24 of the bolt 23 and the O-ring 25 of the flange member 8 and are substantially liquid-sealed by the cylindrical portion 8b of the flange member 8. The oil seal 26 prevents the hydraulic oil leaking from the cylindrical portion 8b from leaking to the outside of the device.

By switching control of the control valve 17 by the control signal of the control device 16, the flow of control oil to the oil passage leading to the advance side hydraulic chamber 19 and the retard side hydraulic chamber 20 is controlled. Specifically, the oil passage 4c formed in the camshaft sleeve 4 communicating with the advance side hydraulic chamber 19, the oil passage 2a formed in the bolt 2, and the oil passage 1 formed in the camshaft 1.
By connecting or disconnecting a with the oil pump 21 and the drain 22, the hydraulic pressure in the advance-side hydraulic chamber 19 is controlled. Further, the oil passage 4d formed in the camshaft sleeve 4 communicating with the retard side hydraulic chamber 20 and the oil passage 1b formed in the camshaft are connected to or cut off from the oil pump 21 and the drain 22, so that the retard side hydraulic pressure is increased. The hydraulic pressure in the chamber 20 is controlled. The control member 9 is moved or stopped in the axial direction depending on the balance between the hydraulic pressures of the advance side hydraulic chamber 19 and the retard side hydraulic chamber 20.

Compared with the advance side hydraulic chamber 19, the retard side hydraulic chamber 2
When the hydraulic pressure of 0 is increased, the control member 9 moves in the arrow P direction shown in FIG. At this time, due to the twisting action of the helical spline, a force in the rotational direction acts on the internal tooth helical spline 7a of the sprocket sleeve 7 and a rotational direction acts on the external tooth helical spline 4a of the camshaft sleeve 4, as shown in FIG. A reverse (positive torque) force acts. Therefore, the timing pulley 5 and the camshaft 1 relatively rotate in a direction in which the rotation phase of the camshaft 1 lags behind the rotation phase of the timing pulley 5 (retard angle direction).

On the other hand, when the hydraulic pressure in the advance side hydraulic chamber 19 is made higher than that in the retard side hydraulic chamber 20, the control member 9 moves in the direction of arrow Q shown in FIG. At this time, as shown in FIG. 6, a force in the direction opposite to the rotational direction acts on the internal tooth helical spline 7a of the sprocket sleeve 7, and a rotational direction (negative torque) acts on the external tooth helical spline 4a of the camshaft sleeve 4. Force of. Therefore, the timing pulley 5 and the camshaft 1 relatively rotate in a direction (advancing direction) in which the rotational phase of the camshaft 1 advances with respect to the rotational phase of the timing pulley 5.

According to the first embodiment of the present invention, the external tooth helical splines 141 and 142 and 101 and 10 are provided by providing a missing tooth between the external tooth helical splines 142 and 101.
The external tooth helical splines 142 and 10
1 is widened and a missing tooth is provided between the internal tooth helical splines 104 and 143, so that the internal tooth helical splines 104 and the internal tooth helical splines 104 are different from the internal tooth helical splines 103 and 104 and 143 and 144. By widening the distance between the cut lines 105 and 143, the cutting portions 105 and 145 prevent the spline from being divided. Therefore, since burrs do not occur on the tooth surface, there is no need for deburring work, and there is an effect that the number of processing steps is reduced.

Further, since the spline is not divided, a spline having a short tooth width does not occur, and abnormal wear and chipping or cracking of the tooth due to concentration of the transmission torque distribution are prevented, so that durability and reliability of the arc gear are improved. Is improved.
(Second Embodiment) A second embodiment of the present invention is shown in FIG. The second embodiment is another example of the method for preventing the spline from being divided by the cutting portion when manufacturing the arc gear.

The arc gears 30, 34 are manufactured by dividing one cylindrical gear into four on the circumference. The external tooth helical splines 341, 342, 301, 302 and the internal tooth helical splines 303, 304, 343, 344 are formed at equal intervals. The intervals between the splines are widened by reducing the number of teeth of the splines within a range that does not cause a problem in strength, so that the cutting parts 305 and 345 prevent the splines from being divided.

Further, in the cutting parts 305 and 345,
The rightmost external tooth helical spline 342 of the arc gear 34 shown in FIG. 7A starts from the upper end 345a, and
The pitch of the external tooth helical splines is set so that the leftmost external tooth helical spline 301 of the arc gear 30 shown in (A) ends at the lower end 305b. Similarly,
The rightmost internal tooth helical spline 304 of the arc gear 30 shown in FIG.
The pitch of the internal tooth helical splines is set so that the leftmost internal tooth helical spline 343 of the arc gear 34 shown in (B) ends at the lower end 345b of the cutting portion 345.

According to the second embodiment of the present invention, since the spline divided by the cutting portion does not occur, the deburring work on the tooth surface is unnecessary as in the first embodiment, and the processing man-hour is reduced. Further, since splines having a short tooth width do not occur and abnormal wear due to concentration of the transmission torque distribution and chipping or cracking of teeth are prevented, the durability and reliability of the arc gear are improved.

In addition to the methods of the first and second embodiments, it is possible to prevent the spline from being divided by the cutting portion by adjusting the inclination angle of the spline.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a method of manufacturing an arc gear according to a first embodiment of the present invention, and FIG. 1 (A) is a schematic view showing cutting parts of external teeth of the arc gear of the first embodiment, (B) It is a schematic diagram which shows the cutting | disconnection part of the internal tooth of the arc-shaped gearwheel of 1st Example.

FIG. 2 is a vertical sectional view showing a valve timing adjusting device for an internal combustion engine according to a first embodiment of the present invention.

FIG. 3 is a plan view showing a control member according to the first embodiment of the present invention.

4 is a sectional view taken along line IV-O-IV shown in FIG.

5 is a cross-sectional view taken along line V-O-V shown in FIG.

FIG. 6 is an explanatory diagram showing the operation of the valve timing adjusting device for an internal combustion engine according to the first embodiment of the present invention.

FIG. 7 is an explanatory view showing a method of manufacturing an arc gear according to a second embodiment of the present invention, and FIG. 7 (A) is a schematic view showing a cutting portion of external teeth of the arc gear of the second embodiment; (B) It is a schematic diagram which shows the cutting | disconnection part of the internal tooth of the arc-shaped gearwheel of 2nd Example.

FIG. 8 is an explanatory view showing a conventional method for manufacturing an arc gear, (A) is a schematic view showing a cut portion of an external tooth of the conventional arc gear, and (B) is a view showing a conventional arc gear. It is a schematic diagram which shows the cutting part of an internal tooth.

[Explanation of symbols]

1 camshaft (camshaft) 4 camshaft sleeve (rotation transmission member) 4a external tooth helical spline 5 timing pulley (crankshaft side member) 7 sprocket sleeve (crankshaft side member) 7a internal tooth helical spline 7b internal cylinder 7g external surface 8 Flange member (crank shaft side member) 8b Cylindrical part 9 Controlling members 10, 14 Arc gears (gear of arc cross section) 10a, 14a Internal tooth helical splines 10b, 14b External tooth helical splines 11 Pin 12 Retainer ring 13 Piston Portion 14c Spring holder 15 Spring 19 Hydraulic chamber 20 Hydraulic chamber 21 Oil pump 22 Drain 30, 34 Arc gear (gear of arc cross section) 105, 145 Cutting portion 101, 102, 141, 142 Internal tooth helical spline 103 104 104 143 144 External tooth helical Splines 305, 345 Cutting parts 301, 302, 341, 342 Internal tooth helical splines 303, 304, 343, 344 External tooth helical splines

Claims (2)

(57) [Claims] 1. A camshaft for driving at least one of an intake valve and an exhaust valve of an internal combustion engine,
A cam shaft side member that is fixed to the cam shaft and includes a rotation transmitting member that rotates integrally with the cam shaft; a crank shaft side member that rotates in synchronization with a crank shaft of an internal combustion engine; and a cam shaft side member. At least one of the teeth provided on the inner and outer circumferences that meshes with the crankshaft side member is a helical tooth, and the crankshaft side member and the camshaft side member are moved by moving in the axial direction. And a control member that relatively rotates the control member , wherein the control member has a cylindrical integrated gear formed by combining a plurality of gears having an arc-shaped cross section, and the gear having the arc-shaped cross section has an inner periphery thereof. Alternatively, there is a helical tooth on the outer circumference, and the helical tooth at the circumferential end portion is provided in a valve timing adjusting device for an internal combustion engine that is obliquely provided continuously from one axial end to the other axial end.
A method of manufacturing a control member according to claim 1, wherein a cylindrical gear having helical teeth is formed on at least one of inner and outer circumferences.
The process of forming and cutting this cylindrical gear along the plane passing through the diameter and the cylinder axis,
The cylindrical tooth so that the cutting surface of the tooth does not cross the helical tooth.
Combining the process of cutting the car and the plurality of gears of the arc-shaped section obtained by cutting
A step of forming a cylindrical integrated gear, and by providing a toothless portion on a part of the cylindrical gear,
Cut the cylindrical gear so that its cross section does not cross the helical teeth.
Valve timing adjustment of internal combustion engine characterized by disconnection
Manufacturing method of an alignment device. 2. Only a helical tooth on the cut surface is a toothless tooth.
The valve for an internal combustion engine according to claim 1, wherein
Method of manufacturing timing adjustment device.