JP3044296U - Variable valve timing device - Google Patents

Abstract

(57) [PROBLEMS] To improve the responsiveness of movement of a piston member, improve the movability of the piston member, and simplify the manufacturing process. A transmission member is provided so as to be rotatable relative to a cam shaft that operates an engine valve, and a rotating member that is integrally rotatable with the cam shaft and has a helical spline formed on an outer peripheral surface thereof. And a piston member that is attached to the camshaft so that the camshaft can move in the axial direction and that has a helical spline that meshes with the helical spline of the rotating member. In the variable valve timing device, at least one of the rotating member and the helical spline of the piston member has a toothless portion, and a front end and a rear end of the piston member along the camshaft axial direction are provided via the toothless portion. A toothless communication port is provided for communication.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a variable valve timing device for changing the opening / closing timing of an engine valve, and more particularly to an improvement of a variable valve timing device of a type in which a front end and a rear end communicate with each other along an axial direction of a cam shaft of a piston member.

[0002]

[Prior art]

 In recent years, in automobile engines, in order to improve output performance and fuel efficiency performance, the opening / closing timing relative to the crank angle of the intake / exhaust valve or the lift amount when the valve is opened can be variably controlled to the optimum state according to the operating state. A variable valve controller is used. As an example of this variable valve control device, a piston member having a helical spline on the inner and outer peripheral surfaces is provided between the camshaft and the camshaft pulley, and this piston member is hydraulically moved in the axial direction of the camshaft, and the helical action is performed. 2. Description of the Related Art A hydraulic variable valve timing device that relatively rotates a camshaft and a camshaft pulley is known (see Japanese Patent Laid-Open No. 2-2277506). Further, as a method of using an electromagnetic solenoid, a rotating member integrally provided at the shaft end of the camshaft, a cylindrical member protruding from the camshaft pulley to the rotating member side, and a gap formed by the rotating member and the cylindrical member are provided. A cylindrical member and a piston member that is fitted to the rotating member via a helical mechanism. The braking force of the electromagnetic solenoid moves the piston member in the axial direction of the camshaft, and the helical action causes the camshaft and camshaft pulley to move. Rotate relative. In the above device, the oil passage is provided in the main body of the piston member from the viewpoint of improving the responsiveness of the piston member due to the back pressure of the hydraulic oil and the lubricating oil. FIG. 4 shows an oil passage of an electromagnetic solenoid type device. An oil passage for allowing lubricating oil to communicate with the main body of the piston member 29 between the cylindrical member 23 and the rotating member 21 in the axial direction. 53 is provided.

[0003]

[Problems to be solved by the device]

 However, a large number of the oil passages 53 cannot be provided due to the problem of the strength of the piston member 29. Therefore, the amount of lubricating oil that passes through is small, and the fluidity thereof is not improved. There is a technical issue that does not improve. Moreover, since the cross-sectional area of the oil passage 53 provided in the main body of the piston member 29 is wider than the cross-sectional area of the gap formed by the piston member 29, the cylindrical member 23, and the rotating member 21, the oil is oil passage 53. Since the helical spline 29a of the piston member 29 and the helical spline 23a of the cylindrical member 23 are engaged with each other, or the helical spline 29b of the piston member 29 and the helical spline 21a of the rotating member 21 are engaged with each other. There is a technical problem that the amount of oil passing through the gap between the parts is small and the friction between the piston member 29 and the cylindrical member 23 and the rotating member 21 is not reduced. Further, in order to provide the oil passage 53 in the main body of the piston member 29, it is necessary to separately process it in the manufacturing process, and there is a problem that the manufacturing process becomes complicated. The above problems similarly exist in the hydraulic variable valve timing device.

Therefore, the present invention has been made to solve the above technical problems, and improves the responsiveness of movement of the piston member, improves the movability of the piston member, and simplifies the manufacturing process. A variable valve timing device is provided.

[0005]

[Means for Solving the Problems]

 That is, according to the first aspect of the present invention, the transmission member is provided so as to be rotatable relative to the cam shaft for operating the valve of the engine, the transmission member is integrally rotatable with the cam shaft, and the helical spline is provided on the outer peripheral surface. And a piston member having a helical spline that meshes with the helical spline of the rotating member and is attached to the cam shaft so that the cam shaft can move in the axial direction. With the pair of helical splines, the axial moving force of the piston member is transmitted to the rotating member as a rotational movement, and the cam shaft integral with the rotating member is relatively rotated with respect to the transmitting member. In the variable valve timing device for changing the opening / closing timing of the valve, At least one of the material and the helical spline of the piston member has a toothless portion, and a toothless communication port for communicating the front end and the rear end of the piston member along the camshaft axial direction through the toothless portion is provided. It is characterized by that.

In the above invention, both the case where the helical spline of one of the rotary member and the piston member has a missing tooth and the case where the helical spline of the rotary member and the piston member has a missing tooth are included. The number of missing teeth of the helical spline includes both one case and plural cases, but it is preferable to provide a plurality of areas from the viewpoint of increasing the oil passage amount and improving the fluidity of the oil.

The operation of the present invention is such that, when the piston member moves in the axial direction of the camshaft, the rotating member or the toothless communication port provided in the helical spline of the piston member causes the front end along the axial direction of the piston member to move. Since the amount of oil passing between the rear ends is increased, the fluidity of the oil is improved and the responsiveness of mobility of the piston member is improved. In addition, by allowing the oil to pass through the toothless communication port, the lubricating oil is distributed to the helical splines around the toothless communication port, reducing the friction between the piston member and the rotating member, and moving the piston member. Improve sex. In addition, since the toothless communication port can be processed at the same time when the helical spline is formed, it is not necessary to separately process it, and the manufacturing process is simplified.

According to a second aspect of the present invention, a transmission member provided so as to be rotatable relative to a cam shaft for operating an engine valve, a transmission member provided integrally with the cam shaft, and a helical spline on an outer peripheral surface thereof. A rotating member having a circular groove and a cylindrical member with a helical spline formed on the inner peripheral surface of the transmitting member and the transmitting member, and the cam shaft can move in the axial direction. And a piston member having an inner peripheral surface that meshes with the helical spline of the rotary member and an outer peripheral surface that has a helical spline that meshes with the helical spline of the cylindrical member. A pair of helical splines make the axial moving force of the piston member a positive rotational motion. Is transmitted to the rotating member and is transmitted to the cylindrical member as a rotational movement in the opposite direction to relatively rotate the cam shaft integral with the rotating member and the transmitting member integral with the cylindrical member. A variable valve timing device for changing the opening / closing timing of a valve, wherein at least one of the helical splines of the cylindrical member, the rotating member or the piston member has a toothless portion, and the piston member has a toothless portion through the toothless portion. It is characterized in that it is provided with a toothless communication port for communicating a front end and a rear end along the axial direction of the cam shaft.

In the above invention, one helical spline of the rotating member, the cylindrical member, or the piston member is used as a toothless member, and the cylindrical member and the piston member, the piston member and the rotating member, or the rotating member and the cylindrical member. Both the case where the helical spline of the member has a missing tooth, the case where the helical spline of the rotating member, the cylindrical member, and the piston member has a missing tooth are included.

As an operation of the present invention, when the piston member moves in the axial direction of the camshaft, the toothless communication port provided in the rotary member, the cylindrical member or the helical spline of the piston member causes the piston member to move along the axial direction of the piston member. Increase the amount of oil passing between the front and rear ends. In addition, by allowing the oil to pass through the toothless communication port, the lubricating oil can be spread to the helical splines around the toothless communication port. In addition, the toothless communication port can be processed at the same time when forming the helical spline.

According to a third aspect of the present invention, a transmission member is provided that is rotatable relative to a cam shaft that operates an engine valve, the transmission member is integrally rotatable with the cam shaft, and a helical spline is provided on an outer peripheral surface of the transmission member. A rotating member having a circular groove and a cylindrical member with a helical spline formed on the inner peripheral surface of the transmitting member and the transmitting member, and the cam shaft can move in the axial direction. And a helical spline that meshes with the helical spline of the cylindrical member on the outer peripheral surface, and a helical spline that meshes with the helical spline of the rotating member on the inner peripheral surface, and a thread groove on the outer peripheral surface. The formed piston member and the piston member are provided so as to be rotatable relative to each other, and A drum member formed with a screw groove that meshes with the screw groove of the piston member; an engagement / disengagement member that is detachably connected to the drum member; and a disengagement member that disconnects the engagement / disengagement member from the drum member. When the solenoid means that is capable of generating a suction force that allows the drum member to rotate relative to each other and the drum member that can rotate relative to each other, a braking force that causes the drum member to rotate relative to the piston member is generated. And a braking means provided so that the relative rotational force of the drum member with respect to the piston member is transmitted to the piston member as axial movement by the drum member and the thread groove of the piston member, The two sets of helical splines transmit the moving force of the piston member in the axial direction to the rotating member as a rotational movement in the positive direction, and the rotational movement in the opposite direction. Then, the variable valve timing is transmitted to the cylindrical member to relatively rotate the cam shaft integrated with the rotating member and the transmission member integrated with the cylindrical member to change the opening / closing timing of the valve. In the device, at least one of the helical splines of the cylindrical member, the rotating member, or the piston member has a toothless portion, and a front end and a rear end of the piston member along the axial direction of the cam shaft are provided through the toothless portion. It is characterized by having a toothless communication port for communicating the ends.

In the above invention, one helical spline of the rotating member, the cylindrical member, or the piston member is used as a toothless member, and the cylindrical member and the piston member, the piston member and the rotating member, or the rotating member and the cylindrical member. Both the case where the helical spline of the member has a missing tooth, the case where the helical spline of the rotating member, the cylindrical member, and the piston member has a missing tooth are included.

According to the operation of the present invention, when the piston member moves in the axial direction of the camshaft, the toothless communication port provided in the rotary member, the cylindrical member, or the helical spline of the piston member causes the piston member to move along the axial direction of the piston member. Increase the amount of oil passing between the front and rear ends. In addition, by allowing the oil to pass through the toothless communication port, the lubricating oil can be spread to the helical splines around the toothless communication port. In addition, the toothless communication port can be processed at the same time when forming the helical spline.

[0014]

[Embodiment of the invention]

 Hereinafter, embodiments to which the present invention is applied will be described in detail with reference to FIGS. {Embodiment 1} FIG. 1 is a sectional view of Embodiment 1 in which the present invention is applied to a variable valve timing device. The variable valve timing device according to the present embodiment includes a rotary member 21 integrally fixed to an axial end of a camshaft 10 and a camshaft pulley as a transmission member rotatably provided on an outer peripheral surface of the camshaft 10. 22, a cylindrical member 23 integrally rotatably provided with the camshaft pulley 22, a drum 24 as a drum member arranged coaxially with the cylindrical member 23, and a torsion spring fixed to the drum 24 and the cylindrical member 23. 25, the engagement / disengagement member 26 provided on the opposite side of the torsion spring 25 and the drum 24, the solenoid 27 facing the engagement / disengagement member 26, and the clutch facing the drum 24 radially outside the solenoid 27. From the solenoid 28 and the piston member 29 arranged in the gap formed by the rotating member 21 and the cylindrical member 23, Further, a stopper 31 that is narrowly provided between the cam shaft 10 and the rotating member 21, a spring 32 that biases the piston member 29 toward the cam shaft pulley 22 side, and a spring 32 that is provided between the drum 24 and the rotating member 21. Bearing member 33, a bearing receiving member 34 that receives the bearing member 33, a fixing member 35 that fixes the bearing receiving member 34 and the rotating member 21, and a fixing member 36 that fixes the bearing member 33 and the drum 24. An engagement / disengagement urging member 37 for urging the disengagement member 26 toward the drum 24, an urging receiving member 38 for receiving the engagement / disengagement urging member 37, and a set screw 39 for fixing the rotating member 21 and the camshaft 10. It is composed of a stopper 41 for fixing the camshaft pulley 22 and the cylindrical member 23.

FIG. 2 is a perspective view of each component according to the present embodiment. The rotating member 21 has a cylindrical main body portion provided with a helical spline 21 a that engages with the piston member 29 on the peripheral surface, a diameter reduced from the main body portion coaxially with the main body portion, and an engaging / disengaging member 26 at the edge portion. It is composed of a columnar protrusion provided with a mating locking groove 21b.

The camshaft pulley 22 is composed of a cylindrical main body portion having an engagement groove 22 a for engaging the timing belt on the outer periphery, and a disc-shaped inscribed disc portion inscribed in the main body portion. The contact disc part has a circular opening in the center and a small circular opening in the circumferential direction.

The cylindrical member 23 includes a cylindrical main body portion and a cylindrical cylindrical portion inside the main body portion, and a helical spline 23a engaging with the piston member 29 is provided on the inner peripheral surface of the cylindrical portion. A part of the helical spline 23a is formed as a toothless portion, and a toothless communication port 51 for passing the lubricating oil in the axial direction is provided.

The drum 24 has a cylindrical main body having an inner peripheral surface provided with a thread groove 24a for engaging with the piston member 29, and a collar portion 24b concentrically protruding in the radial direction from the peripheral edge of the main body end. A ring-shaped engaging tooth 24c that engages with the engagement / disengagement member 26 is formed on the concentric surface of the flange portion 24b, and is rotatable relative to the piston member 29.

The torsion spring 25 has a spirally wound shape in the axial direction, and is made of steel, for example.

The engagement / disengagement member 26 includes a disc-shaped disc portion having a circular opening in the center thereof and a cylindrical cylindrical portion protruding toward the solenoid 27, and is provided on a surface facing the drum 41. The engaged tooth 26a that engages with the engaging tooth 24c provided on the flange of the drum 41, and the engaged groove that engages with the engaging groove 21b of the rotating member 21 on the inner peripheral surface of the opening. 26b is provided.

The piston member 29 has a cylindrical main body portion on the outer peripheral surface of which a helical spline 29a that engages with the helical spline 23a of the cylindrical member 23 is provided, and the piston member 29 protrudes from the main body portion toward the drum 24 side and the outer peripheral surface of the drum 24. A helical spline 29b that engages with the helical spline 21a of the rotating member 21 is formed on the inner peripheral surface of the main body and the cylindrical portion, and is formed of a cylindrical portion provided with a screw groove 29c that engages with the screw groove 24a. A part of the helical spline 29b has a missing tooth, and a missing tooth communication port 52 is provided to allow the lubricating oil to pass through in the axial direction.

The solenoid 27 and the clutch solenoid 28 are hollow cylinders. A coil is incorporated in the hollow portion of the cylinder in the circumferential direction, and the coil is connected to the outside.

FIG. 3 is an enlarged view of the toothless communication port according to the present embodiment. The toothless communication port 51 has a cross-section with a part of the helical spline 23a of the cylindrical member 23 as a toothless portion at the engaging portion of the helical spline 23a of the cylindrical member 23 and the helical spline 29a provided on the outer peripheral surface of the piston member 29. It has a trapezoidal shape. Further, in the toothless communication port 52, a part of the helical spline 29b of the piston member 29 is not provided at the engaging portion between the helical spline 29b provided on the inner peripheral surface of the piston member 29 and the helical spline 21a of the rotating member 21. The teeth are formed in a substantially trapezoidal cross section. Here, since the toothless communication ports 51, 52 are processed at the same time when the helical splines 23a, 29b are formed, a separate step for processing the toothless communication ports 51, 52 is not required. Further, the toothless communication ports 51, 52 may be provided at a plurality of locations from the viewpoint of increasing the amount of lubricating oil that passes, and by design, any of the rotating member 21, the cylindrical member 23, or the piston member 29 may be provided. It may be provided on the helical splines 21a, 23a, 29a, 29b.

Next, the operation of the variable valve timing device according to the present embodiment will be described with reference to FIGS. When the solenoid 27 is not energized, the engagement / disengagement member 26 is urged toward the drum 24 by the urging force of the engagement / disengagement urging member 37, so that the engaging teeth 24c and the engaged teeth 26a are engaged with each other. The drum 24 and the rotary member 21 rotate integrally with each other, and the relative rotational phase of the camshaft 10 and the camshaft pulley 22 is maintained.

First, in order to enable relative rotation of the drum 24 that rotates integrally with the camshaft 10, a current for disconnecting the engagement / disengagement member 26 from the drum 24 is applied to the solenoid 27, and a clutch solenoid 28 is applied. Supplies a current for applying a braking force that maintains the original relative rotation phase of the drum 24 with respect to the piston member 29. Then, the engagement / disengagement member 26 is disconnected from the drum 24, and the drum 24 maintains the original relative rotation phase in a state of being relatively rotatable with respect to the piston member 29.

Next, when the current applied to the clutch solenoid 28 is increased and a braking force for relative rotation is applied to the drum 24, the drum 24 rotates relative to the piston member 29 and, at the same time, the torsion spring 25. Is tightened up. At this time, the relative rotational force of the drum 24 is transmitted to the piston member 29 as a moving force in the axial direction of the piston member 29 by the screw groove 24a on the inner peripheral surface of the drum 24 and the screw groove 29c on the outer peripheral surface of the piston member 29. 29 is moved in the axial direction. Here, since the toothless communication ports 51, 52 are configured to increase the amount of oil passing between the front end and the rear end along the axial direction of the piston member, the fluidity of the oil is improved and the piston member is improved. Mobility response is improved. Further, since the oil passes through the toothless communication ports 51 and 52, the lubricating oil is distributed to the helical splines 21a, 23a, 29a and 29b around the toothless communication ports. The friction between the rotating member 21 and the cylindrical member 23 is reduced, and the movability of the piston member 29 is improved.

The moving force of the piston member 29 in the axial direction is transmitted to the rotating member 21 as a rotary motion by the rotating member 21 and the helical splines 21a and 29b on the inner peripheral surface of the piston member 29, and a cam integrated with the rotating member 21 is provided. The shaft 10 is rotated relative to the camshaft pulley 22 in the clockwise direction, for example. Similarly, the cam shaft pulley 22 is rotated with respect to the cam shaft 10 in the counterclockwise direction from the helical spline 29a on the outer peripheral surface of the piston member 29 and the helical spline 23a on the inner peripheral surface of the cylindrical member 23, respectively. The relative rotational phase difference of the cam shaft 10 is increased.

When the camshaft 10 and the camshaft pulley 22 reach the target relative rotational phase difference, the solenoid 27 is de-energized. At this time, the engagement / disengagement member 26 is moved to the drum 24 side by the urging force of the engagement / disengagement urging member 37, the engagement tooth 24c and the engaged tooth 26a are engaged, and the engagement / disengagement member 26 and the drum 24 are connected. To be done. As a result, the relative rotational phase difference between the camshaft 10 and the camshaft pulley 22 is maintained, and the valve opening / closing timing is changed.

As described above, according to the present embodiment, the fluidity of the lubricating oil is improved and the movable response of the piston member 29 is improved. Further, since the frictional resistance between the piston member 29 and a member contacting the piston member 29 is reduced, the movability of the piston member 29 is improved. Further, there is no need to provide a separate process for processing the toothless communication ports 51, 52, and the manufacturing process is simplified.

The embodiment of the present invention is not limited to the electromagnetic solenoid type variable valve timing apparatus of the present embodiment, and hydraulic oil is used to move the piston member in the axial direction of the camshaft. Alternatively, the moving force may be transmitted as a relative rotational movement of the camshaft by a helical spline to change the opening / closing timing of the valve to a hydraulic variable valve timing.

[0031]

[Effect of the invention]

 According to the present invention, since the amount of oil passing between the front end and the rear end along the axial direction of the piston member is increased, the fluidity of oil is improved and the movable response of the piston member is improved. To do. Further, since the oil is made to spread around the toothless communication port, the frictional resistance between the piston member and other members is reduced, and the movability of the piston member is improved. In addition, since the toothless communication port is processed at the same time as the formation of the hailical spline, it is not necessary to separately process it, and the manufacturing process is simplified.

[Submission date] June 25, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0030

[Correction method] Change

[Correction contents]

[0030] Incidentally, embodiments of the present invention is not limited to the variable Barubuta timing device of an electromagnetic solenoid type in this embodiment, to move the piston member in the axial direction of the mosquito Mushafuto using a hydraulic oil Alternatively, the moving force may be transmitted as a relative rotational movement of the camshaft by a helical spline to change the opening / closing timing of the valve to a hydraulic variable valve timing.

[Brief description of the drawings]

FIG. 1 shows a first embodiment in which the present invention is applied to a variable valve timing device.

FIG. 2 shows a structure of each component according to FIG. 1 from a perspective direction.

FIG. 3 is a view showing a missing tooth communication port according to FIG. 1;

FIG. 4 shows an oil passage according to the related art.

[Explanation of symbols]

 10 camshaft 21 rotating member 22 camshaft pulley (transmission member) 23 cylindrical member 24 drum (drum member) 25 torsion spring 26 engagement / disengagement member 27 solenoid (solenoid means) 28 clutch solenoid (braking means) 29 piston members 51, 52, Missing tooth communication port 53 oil passage

Claims (3)

[Utility model registration claims] 1. A transmission member provided so as to be rotatable relative to a cam shaft for operating a valve of an engine; and a transmission member provided so as to be integrally rotatable with the cam shaft,
A rotary member having a helical spline formed on the outer peripheral surface thereof, and a piston having a helical spline that meshes with the helical spline of the rotary member and is attached to the camshaft so as to be movable in the axial direction of the camshaft. A pair of helical splines, by which the axial moving force of the piston member is transmitted to the rotary member as a rotary motion, and the cam shaft integral with the rotary member is relative to the transmission member. In a variable valve timing device that changes the opening / closing timing of the valve by relatively rotating, at least one of the rotary member or the helical spline of the piston member has a toothless portion, and the piston member of the piston member is provided through the toothless portion. A missing tooth that connects the front end and the rear end along the camshaft axial direction. Variable valve timing system characterized by comprising a through hole. 2. A transmission member rotatably provided relative to a cam shaft for operating a valve of an engine; and a transmission member integrally rotatably provided on the cam shaft,
A rotating member having a helical spline formed on the outer peripheral surface thereof, a cylindrical member having a helical spline formed on the inner peripheral surface thereof while being integrally rotatable with the transmission member, and the cam shaft extending in the axial direction of the cam shaft. And a piston member on the inner peripheral surface of which a helical spline that meshes with the helical spline of the rotating member and an outer peripheral surface of which a helical spline that meshes with the helical spline of the cylindrical member are formed. The two sets of helical splines transmit the axial moving force of the piston member to the rotary member as a positive rotational motion and to the cylindrical member as a reverse rotational motion, thereby rotating the rotary member. By relatively rotating the camshaft and the transmission member that are integral with the cylindrical member, In the variable valve timing device for changing the opening / closing timing of the valve, at least one of the cylindrical member, the rotating member, and the helical spline of the piston member has a toothless portion, and the piston member has the toothless portion through the toothless portion. A variable valve timing device comprising a toothless communication port for communicating a front end and a rear end along the camshaft axial direction. 3. A transmission member provided so as to be rotatable relative to a cam shaft for operating a valve of an engine; and a transmission member provided so as to be rotatable integrally with the cam shaft,
A rotating member having a helical spline formed on the outer peripheral surface thereof, a cylindrical member having a helical spline formed on the inner peripheral surface thereof while being integrally rotatable with the transmission member, and the cam shaft extending in the axial direction of the cam shaft. Is attached so that it can be moved, a helical spline that meshes with the helical spline of the cylindrical member is formed on the outer peripheral surface, and a helical spline that meshes with the helical spline of the rotating member is formed on the inner peripheral surface, and further on the outer peripheral surface. A piston member having a thread groove formed therein, a drum member provided so as to be rotatable relative to the piston member, and having an inner peripheral surface formed with a thread groove meshing with the thread groove of the piston member; An engagement / disengagement member that is detachably connected to a member; When the drum member is rotatable relative to the solenoid means that is capable of generating a suction force that allows the drum member to rotate relatively, a braking force that rotates the drum member relative to the piston member can be generated. And a braking means provided, wherein the relative rotational force of the drum member with respect to the piston member is transmitted to the piston member as axial movement by the screw groove of the drum member and the piston member, and the two sets of helical The camshaft integral with the rotary member is transmitted to the rotary member by a spline in the axial direction of the piston member as a positive rotational motion and as a reverse rotational motion to the cylindrical member. And a variable valve for changing the opening / closing timing of the valve by relatively rotating the transmission member integrated with the cylindrical member. In the timing device, at least one of the cylindrical member, the rotating member, and the helical spline of the piston member has a toothless portion, and a front end and a rear end of the piston member along the camshaft axial direction are provided through the toothless portion. A variable valve timing device comprising a toothless communication port for communicating the ends.