JPH10103114A - Rotational speed detector and valve timing detector using this rotational speed detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotational speed detector, which can surely detect a rotational speed by having noise resistance and high reliability, and a valve timing detector using this rotational speed detector. SOLUTION: A permanent magnet 6 is provided, which makes a yoke 7, 8 capable of integrally rotating by attracting the yoke 8 to a side of the yoke 7 with an inflow of magnetic flux to a side of the yoke 8 in a location where the yokes 7, 8 are opposed adjacent, on the other hand, a DC exciting coil 12 is fixedly arranged, which makes the coil 7, 8 capable of relatively rotating by adjusting attraction force by the permanent magnet with an inflow of magnetic flux to a side of the yoke 8 in an arrangement side thereof. Further, in a magnetic flux route of the permanent magnet in the yoke 8 and the exciting coil, a rotary surface, such as periodically changing an air gap between a side of the yoke 8 and a side of the exciting coil according to rotation of the yoke 8, is provided, by counting a frequency of sinusoidal wave induction voltage generated in the exciting coil, a rotational speed of the yoke 7 is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation speed detecting device and a valve timing detecting device using the same.

[0002]

2. Description of the Related Art Conventionally, as a method for intermittently transmitting torque from one rotating body to another rotating body, a mechanical clutch mechanism, an electromagnetic clutch using an electromagnet, and the like are known. However, since each of these clutch mechanisms controls the transmission of torque by contact / non-contact of the friction material, reliability such as wear of the friction material and changes in the friction coefficient after prolonged use. Had many problems.

On the other hand, a magnet coupling utilizing the attraction force of a permanent magnet is known as a device that transmits torque in a non-contact state. According to this magnet coupling, since there is no contact mechanism, performance degradation is small even after long-time use, and it is excellent in reliability. In addition, in this magnet coupling, it is possible to control the holding torque between the two rotating bodies by the permanent magnet by energizing the exciting coil and adjusting the attraction force of the permanent magnet by the magnetic force. Or
There is an advantage that a relative rotation difference between the two rotating bodies can be detected from a change in impedance of the exciting coil. From such an advantage, it is known that this magnet coupling is applied to a mechanism that makes the valve timing of an engine variable.

[0004]

However, in the conventional magnet coupling, the rotation signal is obtained from the change in the impedance of the exciting coil as described above. However, since the change in the impedance is small in terms of level, However, it is difficult to discriminate the noise, and a problem remains in terms of reliability. In addition, in order to continuously obtain a rotation signal, it is necessary to continuously energize the excitation coil, and in some cases, detection of the rotation signal may be difficult.

Accordingly, the present invention has been made by proposing a rotational speed detecting device capable of reliably detecting the rotational speed with high reliability and a valve timing detecting device using the device.

[0006]

Means for Solving the Problems In the present invention, the following configuration is adopted as specific means for solving such problems.

According to the first aspect of the present invention, the first rotating member and the second rotating member are arranged coaxially, and the first rotating member and the second rotating member are located close to and opposed to each other. In the first rotation member, the magnetic flux flows into the second rotation member side to attract the second rotation member, thereby enabling the first rotation member and the second rotation member to rotate integrally. While the second rotating member is disposed on the side where the second rotating member is disposed.
A DC exciting coil for allowing relative rotation between the first rotating member and the second rotating member by adjusting the attraction force of the permanent magnet by flowing a magnetic flux into the rotating member side of the rotating member; In the magnetic flux path of the permanent magnet and the exciting coil in the second rotating member, an air gap between the second rotating member side and the exciting coil side periodically changes with the rotation of the second rotating member. And the frequency of a sinusoidal induced voltage generated in the exciting coil is counted.

According to a second aspect of the present invention, in the rotation speed detecting device according to the first aspect, the rotating surface of the second rotating member is close to the permanent magnet on a magnetic flux path of the permanent magnet. It is characterized by being provided at a position.

According to a third aspect of the present invention, in the rotation speed detecting device according to the first aspect, the rotating surface of the second rotating member is formed in a circumferential direction of the second rotating member. In addition, the permanent magnet is arranged on one side in the radial direction of the second rotating member, and the excitation coil is arranged on the other side.

[0010] In a fourth aspect of the present invention, in the rotation speed detecting device according to the first aspect, the rotating surface of the second rotating member is formed in a radial direction of the second rotating member. The permanent magnet and the exciting coil are provided on one side in the axial direction of the second rotating member with respect to the rotating surface.

According to a fifth aspect of the present invention, in the rotation speed detecting device according to the first aspect, the direction of the magnetic flux of the exciting coil is set such that the first rotating member and the second rotating member are close to each other. The magnetic flux is set so as to be in the same direction as the direction of the magnetic flux returning to the permanent magnet side through only the second rotating member in the magnetic flux of the permanent magnet at the portion where the magnetic flux is generated.

According to a sixth aspect of the present invention, in the rotation speed detecting device according to the fifth aspect, an auxiliary permanent magnet is provided at a yoke portion of the exciting coil, and a magnetic flux direction of the auxiliary permanent magnet is changed by a magnetic flux of the exciting coil. And the magnetic force of the auxiliary permanent magnet is set to be larger than the magnetic force of the magnetic flux of the permanent magnet flowing into the yoke side of the exciting coil by a predetermined value.

According to a seventh aspect of the present invention, the first rotating member and the second rotating member are arranged coaxially, and the first rotating member and the second rotating member are located close to and opposed to each other. In the first rotation member, the magnetic flux flows into the second rotation member side to attract the second rotation member, thereby enabling the first rotation member and the second rotation member to rotate integrally. While the second rotating member is disposed on the side where the second rotating member is disposed.
A DC exciting coil fixedly disposed to generate a magnetic flux in the rotating member and adjust the attraction force of the permanent magnet to enable relative rotation between the first rotating member and the second rotating member;
Further, a rotating surface is provided in the magnetic flux path of the permanent magnet and the exciting coil in the second rotating member such that an air gap between the exciting coil and the exciting coil periodically changes with rotation, and the rotating surface is generated in the exciting coil. A rotation speed detecting device configured to detect the rotation speed of the second rotating member by counting the frequency of the sine wave induced voltage is mounted on each of the intake side camshaft and the exhaust side camshaft of the engine. In the valve timing detection device, which is configured to detect the valve timing, one of the intake side camshaft and the exhaust side camshaft is provided with a cylinder discriminating means, and the camshaft provided with the cylinder discriminating means is provided. The rotation speed detecting device connects the camshaft to the first rotation member, and the cylinder discriminating cam is not provided. The rotation speed detecting device corresponding to Yafuto is characterized in that the cam shaft coupled to the second rotary member.

According to an eighth aspect of the present invention, the first rotating member and the second rotating member are arranged coaxially, and the first rotating member and the second rotating member are located close to and opposed to each other. In the first rotation member, the magnetic flux flows into the second rotation member side to attract the second rotation member, thereby enabling the first rotation member and the second rotation member to rotate integrally. While the second rotating member is disposed on the side where the second rotating member is disposed.
A DC exciting coil fixedly disposed to generate a magnetic flux in the rotating member and adjust the attraction force of the permanent magnet to enable relative rotation between the first rotating member and the second rotating member;
Further, a rotating surface is provided in the magnetic flux path of the permanent magnet and the exciting coil in the second rotating member such that an air gap between the exciting coil and the exciting coil periodically changes with rotation, and the rotating surface is generated in the exciting coil. A rotational speed detecting device configured to detect the rotational speed of the second rotating member by counting the frequency of the sinusoidal induced voltage is mounted on an engine camshaft to detect valve timing. In the valve timing detection device, the engine crankshaft is provided with cylinder discriminating means,
The camshaft is connected to a second rotating member of the rotation speed detecting device.

[0015]

According to the present invention, the following effects can be obtained by adopting such a configuration.

[0016] The rotation number detecting device according to the first invention of the present application is arranged so that the first rotation member and the second rotation member which are coaxially arranged are close to and opposed to each other. A permanent magnet that allows a magnetic flux to flow into the second rotating member, attracts the second rotating member, and enables the first rotating member and the second rotating member to rotate integrally with each other; On the side where the second rotating member is disposed, a magnetic flux is caused to flow into the second rotating member to adjust the attraction force of the permanent magnet, and the relative rotation between the first rotating member and the second rotating member is adjusted. A DC exciting coil is fixedly arranged, and an air gap between the second rotating member side and the exciting coil side in a magnetic flux path of the permanent magnet and the exciting coil in the second rotating member. Changes periodically with the rotation of the second rotating member. Such a rotating surface is provided to count the frequency of the sinusoidal induced voltage generated in the exciting coil.

According to the rotation speed detecting device of the present invention, when the excitation coil is not energized, the magnetic flux generated by the permanent magnet faces the rotation surface from the rotation surface on the second rotating member side through the air gap. The magnetic flux flows into the exciting coil, and when the exciting coil is energized, the magnetic flux generated by the exciting coil flows through the air gap into the rotating surface of the second rotating member. Therefore, in any of these cases, an induced voltage is generated when the rotating surface rotates with the rotation of the second rotating member. In this case, the air gap periodically changes due to the rotation of the rotating surface, and the magnetic resistance periodically changes accordingly. However, the induced voltage increases when the magnetic resistance changes. For this reason, the voltage value of the induced voltage associated with the rotation of the rotating surface increases and decreases with a sinusoidal characteristic in accordance with the rotation of the rotating surface. By counting the frequency of the sinusoidal induced voltage, the rotation speed of the second rotating member can be detected. In this case, since the change in the induced voltage is larger than the impedance, it is advantageous for noise,
This makes it possible to detect the rotational speed with high reliability.

According to the rotation speed detecting device according to the second invention of the present application, in the rotation speed detecting device according to the first invention, the rotation surface of the second rotation member is
Since the magnetic flux is provided at a position close to the permanent magnet on the magnetic flux path of the permanent magnet, the magnetic flux density in the rotating surface portion is increased, so that an induced voltage having a higher voltage value can be obtained. The reliability of the rotation speed detection based on the voltage is improved.

According to the rotation speed detection device of the third invention of the present application, in the rotation speed detection device of the first invention, the rotation surface of the second rotation member is connected to the rotation surface of the second rotation member. While forming in the circumferential direction,
Since the permanent magnet is arranged on one side in the radial direction of the second rotating member, and the exciting coil is arranged on the other side, even if an axial thrust force acts on the second rotating member, the second rotating member does not have the same effect. The relative position of the second rotating member and the exciting coil in the radial direction, that is, the size of the air gap does not change, so that a stable rotational speed signal can be obtained.

According to the rotation speed detection device of the fourth invention of the present application, in the rotation speed detection device of the first invention, the rotation surface of the second rotation member is connected to the rotation surface of the second rotation member. The permanent magnet and the exciting coil are provided on one side in the axial direction of the second rotating member with respect to the rotating surface while being formed in the radial direction. In the case where the rotating surface is formed in the circumferential direction of the second rotating member and the permanent magnet is arranged on one side in the radial direction of the second rotating member, and the exciting coil is arranged on the other side. In comparison, the device can be made more compact in the axial direction, and other components such as a brake, for example, can be arranged on the other side of the second rotating member by an amount corresponding to the compactness in the axial direction. .

According to the rotation speed detection device of the fifth invention of the present application, in the rotation speed detection device of the first invention, the energizing direction of the exciting coil is set to the first rotation member and the second rotation member. Since the magnetic flux of the permanent magnet is set so as to be in the same direction as the direction of the magnetic flux that returns to the permanent magnet side through only the second rotating member in the magnetic flux of the permanent magnet at a portion where the rotating member is close to and opposed to the rotating member. When the excitation coil is energized to adjust the magnetic flux of the permanent magnet by its magnetic force,
At a portion where the first rotating member and the second rotating member are in close proximity to each other, the magnetic flux on the permanent magnet side is changed from the second rotating member side to the first rotating member side by saturation of the magnetic flux passing therethrough. And the magnetic flux density of the magnetic flux passing through the first rotating member and the second rotating member via the air gap therebetween is reduced, and the relative rotation between the first rotating member and the second rotating member is reduced. Is released, and the relative rotation between them is allowed.

In this case, the magnetic flux density required on the exciting coil side to release the holding state between the first rotating member and the second rotating member is determined by using the above-described magnetic flux saturation. For example, since the magnetic flux direction of the permanent magnet and the magnetic flux direction of the exciting coil are set to be opposite to each other, the magnetic flux of the exciting coil may be smaller than the case where the magnetic flux of the permanent magnet is canceled, so that the energizing voltage of the exciting coil may be reduced. It can be kept lower.

According to the rotation speed detecting device of the sixth invention of the present application, in the rotation speed detecting device of the first invention, an auxiliary permanent magnet is provided in a yoke portion of the exciting coil, and The magnetic flux direction is set in the same direction as the magnetic flux direction of the exciting coil, and the magnetic force of the auxiliary permanent magnet is larger than the magnetic force of the magnetic flux of the permanent magnet flowing into the yoke side of the exciting coil by a predetermined value. You have set. For this reason, in the state where the rotation phase of the first rotating member and the second rotating member is kept in a state in which the exciting coil is not excited, the magnetic flux of the auxiliary permanent magnet causes The magnetic flux flowing from the yoke of the exciting coil to the rotating surface portion is canceled out, and only the magnetic flux of the auxiliary permanent magnet flows from the rotating surface portion to the yoke side of the exciting coil facing the second rotating member. By rotating the rotating surface with the rotation of the member, an induced voltage that increases and decreases in a sinusoidal manner is obtained. By counting the frequency of the induced voltage, the rotation speed of the second rotating member is detected.

Further, the exciting coil is excited from the state in which the rotation phase is held, and the magnetic flux of the excitation coil causes the magnetic flux of the permanent magnet to protrude from the second rotation member side to the first rotation member side, so that the rotation phase is reduced. When the holding is released, the magnetic flux of the exciting coil flows into the rotating surface portion, but the direction of the magnetic flux is the same as the direction of the magnetic flux of the auxiliary permanent magnet. Thus, the magnetic flux of the auxiliary permanent magnet is not canceled out, and the magnetic flux of the auxiliary permanent magnet and the magnetic flux of the excitation coil are both present between the rotating surface and the yoke portion of the excitation coil. As a result, an induced voltage that increases and decreases in a sinusoidal manner is obtained. By counting the frequency of the induced voltage, the rotation speed of the second rotating member is detected. Further, when the excitation coil is de-energized and held in a state where the rotation phase is released, the magnetic flux of the excitation coil in the rotating surface portion disappears, but the magnetic flux of the auxiliary permanent magnet remains as it is. Then, the rotation speed of the second rotating member is detected by the magnetic flux of the auxiliary permanent magnet. That is, according to the present invention, the rotation speed of the second rotating member can be continuously detected even when the control mode is switched between the state in which the rotation phase is held and the state in which the rotation phase is released.

According to the valve timing detecting device of the seventh aspect of the present invention, the first rotating member and the second rotating member are arranged coaxially, and the first rotating member and the second rotating member are arranged. At a position where the first rotating member and the second rotating member are adjacent to each other, a magnetic flux flows into the second rotating member, attracts the second rotating member, and the first rotating member and the second rotating member. While providing a permanent magnet that enables integral rotation with the rotating member, on the side where the second rotating member is disposed, a magnetic flux is generated by the second rotating member to adjust the attraction force of the permanent magnet, and A DC excitation coil that enables relative rotation between the first rotating member and the second rotating member is fixedly arranged, and the exciting coil is further provided in a magnetic flux path of the permanent magnet and the exciting coil in the second rotating member. Air gap periodically changes with rotation A rotation speed detecting device configured to detect the rotation speed of the excitation coil by counting the frequency of a sinusoidal induced voltage generated in the excitation coil is provided on the intake side of the engine. In a valve timing detection device that is mounted on each of a camshaft and an exhaust-side camshaft to detect valve timing, the intake-side camshaft and the exhaust-side camshaft have cylinder discriminating means,
The rotational speed detecting device corresponding to the camshaft provided with the cylinder discriminating means connects the camshaft to the first rotating member, and the rotational speed corresponding to the camshaft not provided with the cylinder discriminating means. Since the detection device connects the camshaft to the second rotation member, the detection device converts the rotation signal of the first rotation member and the rotation signal of the second rotation member into detection signals of the cylinder discriminating means, respectively. As a result, the rotational phase amounts of the intake camshaft and the exhaust camshaft connected to the first rotating member and the second rotating member, respectively, with respect to the crankshaft are detected.

Therefore, according to the valve timing detection device of the present invention, the rotation speed detection device incorporated in the mechanism for holding and releasing the rotation phase of the first rotation member and the second rotation member is used. Can detect the rotation phases of the intake side camshaft and the exhaust side camshaft without separately providing a sensor for detecting the rotational speed of the camshaft, so that the apparatus can be simplified or the cost can be reduced. It is.

According to the valve timing detecting device of the eighth aspect of the present invention, the first rotating member and the second rotating member are arranged coaxially, and the first rotating member and the second rotating member are arranged. At a position where the first rotating member and the second rotating member are adjacent to each other, a magnetic flux flows into the second rotating member, attracts the second rotating member, and the first rotating member and the second rotating member. While providing a permanent magnet that enables integral rotation with the rotating member, on the side where the second rotating member is disposed, a magnetic flux is generated by the second rotating member to adjust the attraction force of the permanent magnet, and A DC excitation coil that enables relative rotation between the first rotating member and the second rotating member is fixedly arranged, and the exciting coil is further provided in a magnetic flux path of the permanent magnet and the exciting coil in the second rotating member. Air gap periodically changes with rotation A rotation speed detecting device configured to detect the rotation speed of the second rotating member by counting the frequency of a sinusoidal induced voltage generated in the excitation coil. In a valve timing detecting device which is mounted on a camshaft and detects valve timing, a cylinder discriminating means is provided on a crankshaft of an engine, and the camshaft is connected to a second rotating member of the rotational speed detecting device. Therefore, the rotation phase amount of the camshaft with respect to the crankshaft can be detected by comparing the rotation signal of the second rotating member with the detection signal of the cylinder discriminating means.

Therefore, according to the valve timing detecting device of the present invention, the rotation speed detecting device incorporated in the mechanism for holding and releasing the rotation phase of the first rotating member and the second rotating member is used. Thus, since the rotation phase of the camshaft can be detected without providing a separate sensor for detecting the rotation speed of the camshaft, the apparatus can be simplified or the cost can be reduced.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be specifically described based on preferred embodiments.

A: First Embodiment FIG. 1 shows a joint mechanism Z ₁ for connecting a camshaft 1 of an engine and a pulley 2 rotationally driven by a crankshaft (not shown) so as to be variable in rotation angle phase. I have. This is joint mechanism Z _1, and the rotation speed detecting apparatus according to the present invention is incorporated, the valve timing of the intake and exhaust valves by utilizing the rotary speed detecting device can be detected.

[0031] A: Configuration joint mechanism Z ₁ of the joint mechanism Z ₁ is intended for connecting the pulley 2 which is relatively rotatably supported on the rotation angle phase variable on the end outer periphery of the cam shaft 1 and the cam shaft 1 The specific structure is as follows.

On the distal end side of the camshaft 1, a hollow long shaft-shaped intermediate shaft 3 having a helical spline 3a engraved on its outer periphery.
And a flanged hollow shaft-shaped boss member 4 externally fitted to the tip of the intermediate shaft 3 are fastened and fixed coaxially to the camshaft 1 by fastening bolts 23. The member 4 rotates integrally with the camshaft 1. The boss member 4 is rotatably supported by the bearing 32 on the casing 11 side.

At the radially outer position of the intermediate shaft 3, a hollow shaft member 5 having a disk portion 5 a and having a screw 5 b engraved on its inner peripheral surface is arranged coaxially with the intermediate shaft 3. . An advancing plate between the inner periphery of the hollow shaft member 5 and the outer periphery of the intermediate shaft 3 simultaneously meshes with the screw 5b on the hollow shaft member 5 side and the helical spline 3a on the intermediate shaft 3 side. 19 are arranged. The advancing plate 19 is connected to the pulley 2 via a claw member 20. Further, a return spring 21 composed of a spiral spring is provided between the pulley 2 and the hollow shaft member 5.

On the other hand, on the outer peripheral side of the boss member 4, FIG.
As shown in FIG. 2, a permanent magnet 6 having a donut shape and a pair of right and left yokes 7 having a donut shape arranged so as to sandwich the permanent magnet 6 in the thickness direction thereof are arranged on an axis. It is attached in a state sandwiched in the direction. in this case,
The yoke 7 has a diameter larger than that of the permanent magnet 6, and has, on its outer peripheral surface, salient poles 7c, 7c,. Also,
On one side of the yoke 7, a circular concave portion 7b is formed. The concave portion 7b is used for positioning and fixing the permanent magnet 6 in the radial and axial directions by fitting the permanent magnet 6 in the axial direction, and has a depth corresponding to the thickness of the permanent magnet 6. It is about 1/3. Therefore, when the pair of yokes 7, 7 and the permanent magnet 6 are assembled, as shown in FIG. 1, an annular annular ridge 7a formed on the outer periphery of one side of each of the yokes 7, 7 is provided. , 7a are opposed at a predetermined interval, and an annular air gap 25 is interposed therebetween.
Will be formed. The boss member 4, the permanent magnet 6, and the yokes 7, 7 are connected to the camshaft 1 and rotate integrally with the camshaft 1, and these members constitute an inner rotor 9. The yoke 7
Corresponds to the “first rotating member” in the claims.

Outside the inner rotor 9 in the radial direction,
A yoke 8 attached coaxially to one end of the hollow shaft member 5 is located. The yoke 8 corresponds to the “second rotating member” in the claims. As shown in FIGS. 1 to 5, the inner diameter of the yoke 8 is larger than the outer diameter of the yoke 7 by a predetermined dimension. Cylindrical portion 8a and cylindrical portion 8a
And a plurality of (four in this embodiment) protruding pieces 8b, 8b,. The protruding pieces 8b, 8b,... Are attached to the disk portion 5a of the hollow shaft member 5 so that the projecting poles 2 protrude from the surface of the disk portion 5a.
9, 29, ... are formed. Therefore, the surface formed by the projecting pieces 8b, 8b,... Of the yoke 8 and the disk portion 5a corresponds to the "rotating surface" in the claims. Also, at the portion of the inner peripheral surface of the cylindrical portion 8a of the yoke 8 which faces the outer peripheral surface of each of the yokes 7, 7, convex poles 8c, 8 formed by ridges extending in the axial direction are provided.
are formed, and these salient poles 8c, 8c,
.. Are closely opposed in the radial direction with the air gap 24 to the protruding poles 7c on the yoke 7 side. Further, in a portion corresponding to the permanent magnet 6 on the inner peripheral surface of the cylindrical portion 8a of the yoke 8, an annular concave groove 26 having the same width dimension as the air gap 25 on the inner rotor 9 side is provided.
Due to the formation of the concave groove 26, a portion of the cylindrical portion 8a corresponding to the concave groove 26 has a smaller sectional area than other portions (hereinafter, this portion is referred to as " Small cross section 27 "). The outer rotor 10 is composed of the yoke 8 and the hollow shaft member 5.

An exciting coil 12 is fixed to the casing 11 side of the yoke 8 radially outside the cylindrical portion 8a, and a pair of yokes 13, 1 having an annular space formed therein.
4 is accommodated in the annular space.
The ends 13a and 14a of the yokes 13 and 14 on the side close to and opposed to the cylindrical portion 8a are separated from each other at a portion corresponding to the permanent magnet 6, and form an air gap 30 therebetween. . In addition, each of the yokes 13 and 14
Of the protruding pieces 8b, 8b,... Of the yoke 8, that is, on the outer surface side of the portion close to and facing the protruding poles 29, 29,. Each salient pole 28, 2
8, a plurality of salient poles 2 corresponding to
8, 28,... Are formed.

Further, a brake coil 16 and a shoe member 17 which is pressed against the disk portion 5a of the hollow shaft member 5 by receiving the magnetic force of the brake coil 16 are provided radially outside the excitation coil 12. Brake 15 is arranged.

[0038] B: To explain the operation, etc. of the joint mechanism actuated such as the joint mechanism Z ₁ of Z ₁ are as follows. The joint mechanism Z ₁ is a pulley 2 which is driven to rotate via the timing belt (not shown) by the cam shaft 1 and the engine crankshaft (not shown),
"Phase holding", in which the rotation phase is held and integrally connected to rotate, and "phase cancellation" in which the phase holding state of the camshaft 1 and the pulley 2 is released to allow the phase of both to be changed. Can be selected according to the operating state of the engine speed. The “phase holding” is performed by the magnetic force of the permanent magnet 6, and the “phase release” is performed by the magnetic force of the exciting coil 12. The adjustment is performed by adjusting the magnetic force of the permanent magnet 6. The “phase change” is performed by the axial displacement of the advancing plate 19 using the braking force of the brake 15 and the restoring force of the return spring 21 as the driving force in the state of “phase release”. Furthermore, in those of this embodiment, and detects the rotational speed of the pulley 2 by effectively utilizing the structure of the joint mechanism Z _1. Hereinafter, each of these operations will be specifically described.

The phase holding "phase hold" is performed in a state where the de-energized to the exciting coil 12 by the magnetic force of the permanent magnets 6. That is, as shown by the actual magnetic flux lines in FIG.
The In state deenergized, the magnetic flux F ₁ generated by the permanent magnet 6, break up into three paths of the first to third magnetic flux F ₁₁ to F _13.

The first magnetic flux F ₁₁ passes through one of the yoke 7 and the air gap 24 from the permanent magnet 6 flows into the projecting piece portion 8b of the yoke 8 through the small section portion 27 portion of the cylindrical portion 8a Again, the air gap 24 and the other yoke 7
And returns to the permanent magnet 6 via

The second magnetic flux F ₁₂ flows into the cylindrical portion 8a of the yoke 8 from the permanent magnet 6 side, and then flows into the cylindrical portion 8a.
Flows further into one yoke 13 of the exciting coil 12, flows from the yoke 13 through the other yoke 14 as it is to the yoke 8 side, and returns to the permanent magnet 6 side again.

The third magnetic flux F ₁₃ is such that the second magnetic flux F ₁₂ branches off at the yoke 14 side and flows from the yoke 14 through the air gap 18 to the projecting piece 8 b side of the yoke 8. A path from the protruding piece portion 8b to the permanent magnet 6 through the cylindrical portion 8a is taken.

When these three magnetic fluxes F _{11 to} F ₁₃ flow across the yokes 7, 7 and the yoke 8, the salient pole 7 c on the yoke 7 side and the salient pole 8 c on the yoke 8 side When they face each other in the radial direction, the density of the magnetic flux flowing between them becomes maximum, and the magnetic force causes the yokes 7, 7 (that is, the camshaft 1 connected thereto) and the yoke 8 (that is, the connection thereto). The relative rotation of the pulley 2) is restricted while maintaining the rotation phase at that time, and both can be integrally rotated. Incidentally, the second magnetic flux F ₁₂ is flowing straddling between the yoke 8 and the yokes 13 and 14, the phase holding force between both of them because they are not formed salient between these With no action, the two can be rotated relative to each other.

The power transmission path in this "phase holding" state is as follows. That is, the hollow shaft member 5 and the intermediate shaft 3 (that is, the cam shaft 1) are integrated by integrating the yoke 7 and the yoke 8 by “phase holding”, and the advancing plate 19 is locked. State. Accordingly, the rotational force of the pulley 2 is transmitted from the pulley 2 to the camshaft 1 through the claw member 20, the advancing plate 19, and the intermediate shaft 3 in that order.

Phase release "phase release" is performed by the magnetic force of the exciting coil 12. That is, as shown by broken magnetic flux lines in FIG. 5, when the exciting coil 12 is excited, the first magnetic flux F ₂₁ circulating in the yokes 13 and 14 is branched from the first magnetic flux F _21. a second magnetic flux F ₂₂ is fed back to the yoke 14 side is generated to flow into the protruding portions 8b side of the yoke 8 in. In this case, since the first magnetic flux direction in the small section portion 27 portion of the yoke 8 of the first magnetic flux F ₁₁ of the magnetic flux F ₂₁ and the permanent magnet 6 side is set in the same direction, the small cross section 2
7, the magnetic flux is saturated, and the first magnet on the permanent magnet 6 side
The first magnetic flux F ₂₁ of the magnetic flux _{F 11} is in the exciting coil 12 side
The is Seridasa the permanent magnet 6 side, as in the magnetic flux F ₁₄ shown in magnetic flux lines broken in the figure, to the yoke 8 side to take a path that circulates only in the yoke 7, 7 side without flowing by Become. As a result, the density of the magnetic flux flowing between the salient pole 7c on the yoke 7 side and the salient pole 8c on the yoke 8 side becomes as small as possible, and the phase cannot be maintained. And the yoke 8 (that is, the relative rotation between the camshaft 1 and the pulley 2) is allowed, and the phase holding state is released.

The phase change "phase change" is performed by the advancing plate 19 using the braking force of the brake 15 and the restoring force of the return spring 21 as driving forces. That is, when a braking force is applied to the hollow shaft member 5 by the brake 15, the hollow shaft member 5 relatively rotates to the advance side or the retard side with respect to the pulley 2, and the rotation of the hollow shaft member 5 is stopped. Then, the advancing plate 19 rotates and moves in the axial direction. As the advancing plate 19 moves in the axial direction, the rotational phases of the advancing plate 19 and the intermediate shaft 3 change to the advance side or the retard side in accordance with the twist angle of the helical spline. As a result, the phase of the camshaft 1 is changed with respect to the pulley 2 in the advance direction or the retard direction.

The pulley 2 and the hollow shaft member 5 rotate relative to each other in accordance with the phase change by the braking force of the brake 15, and the relative rotation causes the return spring 21 to be wound in a direction to increase the restoring force. . Therefore, when the brake 15 is not operated at the time of “phase release”, the restoring force of the return spring 21 acts between the pulley 2 and the hollow shaft member 5,
When the advancing plate 19 moves in the axial direction, the phase of the camshaft 1 is changed in the retard direction or the advance direction with respect to the pulley 2.

It should be noted that any one of the braking force of the brake 15 and the restoring force of the return spring 21 is referred to as "advanced driving force".
Whether to use it as the "phase delay driving force" can be arbitrarily selected according to a desired phase change characteristic.

After the predetermined "phase change" is completed, the exciting coil 12 is de-energized and the permanent magnet 6 is turned off.
"Phase holding" is performed.

[0050] In those detected rotational speed of this embodiment is to detect the number of rotation of the pulley 2 side by effectively utilizing the structure of the joint mechanism Z ₁ of such the above phase variable. That is, the second magnetic flux of the third flux F ₁₃ in the "phase hold" state of the permanent magnet 6 side, also in the "phase cancellation" state of the exciting coil 12 side of the cam shaft 1 and the pulley 2 F ₂₂ is,
It flows between the salient pole 29 of the yoke 8 and the salient pole 28 of the yoke 14 via the air gap 18. And
Since the yoke 14 (i.e., the exciting coil 12) is fixed, the yoke 8
And the exciting coil 12 rotate relative to each other,
8 changes periodically, an induced voltage is generated in the exciting coil 12. In this case, the induced voltage corresponds to a change in the magnetic resistance caused by the periodic change of the air gap 18, and at the time when the magnetic resistance changes, the magnetic flux density increases, so that the induced voltage increases. The induced voltage has a sinusoidal characteristic in which the voltage value periodically increases and decreases. Therefore, by counting the frequency of the induced voltage, the rotation speed of the yoke 8, that is, the rotation speed of the pulley 2, can be detected.

[0051] Thus, in those of this embodiment, some of the components of the joint mechanism Z ₁ (i.e., the yoke 8 and the yoke 14) only by forming the salient 28 and 29 by using the The number of rotations of the pulley 2 can be detected by the magnetic flux of the permanent magnet 6 and the exciting coil 12 without providing any dedicated sensor. In terms of simplification of the structure or promotion of cost reduction, It is advantageous.

In this case, the rotation speed is detected by a change in the induced voltage. This change in the induced voltage is caused by the impedance of the coil used in the conventional rotation speed detection device for detecting the rotation speed. , The rotation signal is hardly influenced by the noise signal, and the rotation speed can be detected with high reliability.

Further, the rotation speed is detected by the yoke 14.
Since the change of the induced voltage due to the magnetic flux flowing between the convex pole 28 on the side and the convex pole 29 of the yoke 8 is used,
The higher the magnetic flux density at each of the salient poles 28 and 29, the higher the induced voltage value is obtained, and the easier it is to detect the rotational speed. From this point of view, in this embodiment,
By providing the formation positions of the square salient poles 28 and 29 as close as possible to the permanent magnet 6, the salient poles 28 and 29 are provided.
The effect of the magnetic flux attenuation at the portion is avoided as much as possible so that a high magnetic flux density can be obtained.

B: Second Embodiment FIG. 6 shows a main part of a joint mechanism Z _{2 according to} a _second embodiment. The joint mechanism Z _2, the first be those having the same basic configuration as the joint mechanism Z ₁ according to the embodiment, it differs from the embodiment of the first, above the exciting coil 12 each The point is that an auxiliary permanent magnet 35 having an annular shape is arranged in the air gap 30 provided between the ends of the yokes 13 and 14. The configuration is such that the salient pole 29 on the yoke 8 side and the salient pole 2 on the yoke 14 side
In detecting the rotational speed of the yoke 8 (ie, the rotational speed of the pulley 2) due to the magnetic flux passing through the pulley 2, the pulley 2 is continuously maintained even when switching between "phase holding" and "hold release". (In other words, output of a rotation signal). That is, the in the case of the first embodiment, the salient 28 and the salient of the third magnetic flux F ₁₃ and the exciting coil 12 side between the permanent magnet 6 side of the 29 second flux F ₂₂ Togagyaku Since the rotation is detected by the third magnetic flux F ₁₃ on the permanent magnet 6 side, for example, the second magnetic flux F on the exciting coil 12 side is changed from the “phase holding” state. At the time of switching to the “phase release” state in which the rotation speed is detected by the rotation speed ₂₂ , the moment when the magnetic flux F ₁₃ and the magnetic flux F ₂₂ cancel each other, the magnetic flux disappears, and the rotation speed cannot be detected. There is.
The purpose of the second embodiment is to prevent the occurrence of such a situation that the rotation speed cannot be detected due to the disappearance of the magnetic flux.

The details are as follows. First, the magnetic flux F ₃ of the auxiliary permanent magnet 35 is applied to the yokes 13 and 14.
A first magnetic flux F ₃₁ for circulating the second magnetic flux F ₃₂ which returns branched from the first magnetic flux F ₃₁ from flowing into the salient 29 side of the yoke 8 to 35 side the auxiliary permanent magnet Take two routes. The direction of the magnetic flux F ₃ is set so as to be the same as the direction of the first magnetic flux F ₂₁ of the exciting coil 12 at a portion corresponding to the small cross section 27 of the yoke 8. The magnetic force of the auxiliary permanent magnet 35 is
The first magnetic flux F ₁₁ of the permanent magnet 6 without causing Seridasa 6 side permanent magnets from the small section portion 27 (i.e., not offset the phase holding action by the permanent magnet 6) and the permanent magnet 6 it is set to such a value that can be canceled second magnetic flux F ₁₂ of.

With such a setting, in the “phase holding” state, the first magnetic flux F ₃₁ of the auxiliary permanent magnet 35 is set.
As a result, the second magnetic flux F ₁₂ of the permanent magnet 6 is canceled, and only the second magnetic flux F ₃₂ of the auxiliary permanent magnet 35 flows between the salient pole 28 and the salient pole 29, and the second magnetic flux F 12 ₃₂
The rotation speed is detected.

On the other hand, from the “phase holding” state to the “hold release”
In switching to, its flux F ₂ the exciting coil 12 is energized is generated, a second magnetic flux F ₂₂ flowing between the salient poles 28 and salient 29 of the magnetic flux F _2, the auxiliary Since the direction of the second magnetic flux F ₃₂ of the permanent magnet 35 is the same as that of the second magnetic flux F ₃₂ , the second magnetic flux F ₃₂ of the auxiliary permanent magnet 35 is affected by the magnetic flux F ₂ of the exciting coil 12. In this case, the rotation speed of the pulley 2 is continuously detected even when the state is switched from the “phase holding” state to the “hold release”.

C: Third Embodiment FIGS. 7 and 8 show a joint mechanism Z according to a third embodiment .
_{The main part of 3} is shown.

[0059] joint mechanism Z ₃ of the structure of the joint mechanism Z ₃ this embodiment, the boss member 43 attached to the distal end of the cam shaft 41, a plurality of salient poles on its outer circumference the permanent magnets 45 (not shown) The boss member 43, the yoke 44, and the permanent magnet 45 constitute the inner rotor 39 by attaching a pair of left and right yokes 44, 44 provided with the above. A cylindrical yoke 46 having a plurality of convex poles formed on an inner peripheral surface thereof is disposed on the outer peripheral side of the inner rotor 39, and a flange member 48 and a hollow shaft are provided on the yoke 46 via an intermediate member 47. The member 38 is attached, and the outer rotor 40 is constituted by the yoke 46, the intermediate member 47, and the flange member 48. Further, a pulley (not shown) is connected to the hollow shaft member 38 via an advancing plate, as in the first and second embodiments. Is provided with a return spring (not shown).

Further, an exciting coil 50 provided with a yoke 51 is arranged radially outside the yoke 46. The brake coil 56 and the magnetic force of the brake coil 56 receive the side of the excitation coil 50 and the inner rotor 39 which are arranged in the radially overlapping state with respect to the flange member 48. A brake 55 having a shoe member 57 to be brought into sliding contact is arranged.

On the other hand, as shown in FIGS. 8 and 9, one end of the yoke 46 has circumferentially extending convex poles 58, 58,.
Are formed, and the salient pole 5 on the yoke 46 side is also formed on the inner peripheral surface on one end side of the yoke 51 of the excitation coil 50.
The convex poles 59, 59,... Extending in the circumferential direction are formed so as to correspond to 8, 58,.

As described above, the inner rotor 39, the yoke 46, and the exciting coil 50 are arranged so as to be overlapped in the radial direction, and the brake 55 is arranged beside the inner rotor 39, the yoke 46, and the exciting coil 50, for example, in the first embodiment. as compared with the case of placing a further brake 15 radially outside of the exciting coil 12 as the joint mechanism Z ₁ in the polymerised state, it becomes possible to shorten the axial length of該継hand placement Z _3.

The operation of the joint mechanism Z ₃ , etc. The “phase holding”, “release of holding” and “phase change” in this joint mechanism Z are the same as those in the case of the joint mechanism Z _{1 according} to the first embodiment. The description is omitted, and only the detection of the rotational speed, which is the gist of the present invention, will be described.

As shown in FIG. 8, in the “phase holding” state, the magnetic flux of the permanent magnet 45 is transmitted from the yoke 44 via the yoke 46 to the convex pole 58 to the yoke 51.
Flows into the side of the convex pole 59. Therefore, when the yoke 46 rotates relative to the exciting coil 50, an induced voltage is generated in the exciting coil 50. By counting the frequency, the rotation speed of the small cross section 46a, that is, the pulley The rotation speed is detected.

On the other hand, in the “released state”, although the magnetic flux lines are not shown in FIG. 8, the magnetic flux is excited by the exciting coil 50 so that the magnetic flux on the side of the permanent magnet 45 at the small section 46 a of the yoke 46 is reduced. Flows in the same direction. Therefore, the magnetic flux on the side of the permanent magnet 45 is pushed out from the side of the yoke 46 toward the permanent magnet 45 due to the magnetic flux saturation at the small cross section 46a, thereby performing "release of holding". In this case, the rotation speed of the yoke 46, that is, the rotation speed of the pulley, is detected by the magnetic flux of the excitation coil 50 flowing between the salient poles 58 and 59.

As described above, the advantages in detecting the rotation speed of the pulley based on the change in the induced voltage are all the same as those in the first and second embodiments.
In addition, especially when the above-mentioned salient poles 58 and the salient poles 59 related to the rotation speed detection are formed in the circumferential direction of the yoke 46 and the yoke 51, respectively, as in this embodiment, for example, a thrust force is exerted on the outer rotor 40 side. Therefore, even if it is displaced in the axial direction, the size of the air gap between them, that is, the magnitude of the magnetic resistance corresponding to the amount of this air gap does not change. Can be obtained more stably, and furthermore, the accuracy of rotation speed detection can be improved.

D: Fourth Embodiment FIGS. 10 and 11 show a joint mechanism Z _{4 according} to a _fourth embodiment.

[0068] Structure The joint mechanism Z ₄ of the joint mechanism Z ₄ is fitted with a yoke 46 serving as the inner rotor 39 to the front end portion of the cam shaft 41. The boss member 43 is disposed radially outside the yoke 46 so as to be relatively rotatable.
The boss member 43, the yokes 44, 44 and the permanent magnet 45 constitute the outer rotor 40. The boss member 43
Is connected to a pulley (not shown) via a hollow shaft member 38.

Further, an exciting coil 50 is disposed radially inward of the yoke 46 while being accommodated in a yoke 51 fixed to the casing 42 side. Further, a brake 55 having a brake coil 56 and a shoe member 57 is disposed at the axially lateral position of the excitation coil 50 and the outer rotor 40 arranged in the radially superposed state. The member 57 receives the magnetic force of the brake coil 56 and slides on the flange member 48 fixed to the hollow shaft member 38 to apply a predetermined braking force to the pulley.

On the other hand, the side surface of the yoke 51 and the side surface of the yoke 46 which are closely opposed to each other via the air gap 36 are provided with convex poles 59 each formed of a radially extending convex streak.
And convex poles 58 are formed at predetermined intervals in the circumferential direction.

[0071] Since the operation or the like of the joint mechanism Z ₄ basic operation of the joint mechanism Z ₄ are the same as the joint mechanism Z ₁ to Z ₃ of each of the above embodiments and a description thereof will be omitted, the gist of the present invention will now Will be mainly described.

In the “phase holding” state, a part of the magnetic flux of the permanent magnet 45 is transferred from the salient pole 58 on the yoke 46 side to the yoke 5 of the exciting coil 50 as shown by the actual magnetic flux line in FIG.
The two convex poles 5 flow into the convex pole 59 on the first side and rotate with the rotation of the yoke 46 (that is, the cam shaft 1).
A periodic change in the magnetic resistance between 8, 59 generates a sinusoidal induced voltage, and the frequency of the induced voltage is counted to detect the rotation speed of the camshaft 41.

In the "hold release" state, the exciting coil 5
A part of the magnetic flux of 0 flows between the salient pole 58 and the salient pole 59,
The rotational speed of the camshaft 1 is detected by the magnetic flux between the two convex poles 58 and 59.

As described above, the joint mechanism Z _{4 of} this embodiment is used.
Is different from the joint mechanisms of the above embodiments in that the number of revolutions of the camshaft 1 can be detected. Therefore,
And it can detect the rotational speed of the camshaft 1 as the joint mechanism Z ₄ in this embodiment, the joint mechanism Z ₁ to Z ₃ in the above embodiments
As described above, the valve timing of the engine can be easily detected without providing a dedicated rotation sensor or the like by appropriately combining with the one capable of detecting the rotation speed of the pulley.
Hereinafter, the valve timing detection device will be described using these joint mechanism Z ₁ to Z _4.

E: Valve Timing Detector FIG. 12 shows a pulley 7 on one end of the exhaust-side camshaft 61 and one end of the intake-side camshaft 62 in the DOHC engine.
1, 72 and the coupling mechanisms 64, 65 are attached, and the respective camshafts 61, 62 are connected to each other via a timing belt 74 which is looped between the respective pulleys 71, 72 and the pulley 73 on the crankshaft 63 side. A drive system that is driven to rotate by a crankshaft 63 is shown. A cylinder discrimination sensor 66 is attached to the camshaft 62. And, in this example, among the respective joint mechanism 64 and 65 provided in the respective cam shafts 61 and 62, one of the joint mechanism 64 is joint mechanism Z ₁ to Z described in the first to third embodiments described above ₃ using a structure capable of detecting the rotational speed of the pulley 71 as in the other joint mechanism 65 is rotational speed of the exhaust camshaft 62 as the joint mechanism Z ₄ described in the fourth embodiment Is used.

With this configuration, as shown in FIG. 13, rotation signals are output from the cylinder discrimination sensor 66 and the joint mechanisms 64 and 65, respectively. Here, the rotation signal of the joint mechanism 64 for detecting the rotation speed of the pulley 71 of the exhaust-side camshaft 61 is used as a reference, and this rotation signal is used as the rotation signal of the joint mechanism 65 for detecting the rotation speed of the intake-side camshaft 62. Cylinder discrimination sensor 6
6, the deviation Δt ₁ in the rotation signal of the cylinder discriminating sensor 66 indicates the valve timing of the exhaust camshaft 61, and the deviation Δt ₂ in the rotation signal of the joint mechanism 65 indicates the intake side. The valve timing of the camshaft 62 will be represented.

Therefore, the cylinder discriminating sensor 66 originally provided for the necessity in engine control and the coupling mechanisms 64 and 65 provided for varying the valve timing.
By using the above, it is possible to easily detect the valve timing of each of the camshafts 61 and 62 without providing a dedicated camshaft rotation speed sensor unlike the related art.

As another example, in the case where a cylinder discriminating sensor 66 is provided on the crankshaft 63 side as shown by a chain line in FIG. 12, for example, the exhaust-side camshaft 61 and the intake-side camshaft are provided. 62, each of the joint mechanisms 6
4 and 65 both have a structure capable of detecting the rotation speed of the camshaft,
The valve timing of the exhaust camshaft 61 and the intake camshaft 62 can be detected by comparing the rotation signal of the cylinder discrimination sensor 66 with the rotation signals of the joint mechanisms 64 and 65 based on the rotation signal of the cylinder discrimination sensor 66. .

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a joint mechanism provided with a rotation speed detecting device according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of a permanent magnet and the like in the joint mechanism shown in FIG.

FIG. 3 is an enlarged view taken along the line III-III of FIG. 1;

FIG. 4 is a view taken in the direction of arrows IV-IV in FIG. 3;

FIG. 5 is an enlarged view of a portion V in FIG. 1;

FIG. 6 is a structural explanatory view of a joint mechanism provided with a rotation speed detecting device according to a second embodiment of the present invention.

FIG. 7 is a longitudinal sectional view of a joint mechanism provided with a rotation speed detecting device according to a third embodiment of the present invention.

FIG. 8 is an enlarged view of a portion VIII in FIG. 7;

9 is a perspective view of a main part of a rotation detecting unit in the joint mechanism shown in FIG. 8;

FIG. 10 is a longitudinal sectional view of a joint mechanism provided with a rotation speed detecting device according to a fourth embodiment of the present invention.

FIG. 11 is an enlarged view of a portion X in FIG. 10;

FIG. 12 is a perspective view showing an arrangement of the joint mechanism on the engine side.

FIG. 13 is an explanatory diagram of a method for detecting a rotation phase amount.

[Explanation of symbols]

1 is a cam shaft, 2 is a pulley, 3 is an intermediate shaft, 4 is a boss member, 5 is a hollow shaft member, 6 is a permanent magnet, 87 is a yoke, 8
Is a yoke, 9 is an inner rotor, 10 is an outer rotor,
11 is a casing, 12 is an exciting coil, 13 and a yoke are yokes 13, 15 are brakes, 16 is a brake coil, 17 is a shoe member, 19 is an advancing plate, 20 is a claw member, 21 is a return spring, and 23 is a fastening. Bolt, 25 is an air gap, 26 is a concave groove, 27 is a small cross section, 28 and 29 are convex poles, 30 is an air gap,
31 to 33 are bearings, 35 is an auxiliary permanent magnet, 38 is a hollow shaft member, 39 is an inner rotor, 40 is an outer rotor,
1 is a cam shaft, 42 is a casing, 43 is a boss member, 44
Is a yoke, 45 is a permanent magnet, 46 is a yoke, 47 is an intermediate member, 48 is a flange member, 49 is an air gap, 50
Is an exciting coil, 51 is a yoke, 52 to 54 are bearings, 55
Is a brake, 56 is a brake coil, 57 is a shoe member, 58 and 59 are salient poles, 61 and 62 are camshafts, 63
Is a crankshaft, 64 and 65 are variable valve timing devices, 66 is a cylinder discrimination sensor, and 67 is a detector.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02P 7/067 302 F02P 7/067 302Z G01P 3/488 G01P 3/488 F

Claims (8)

[Claims] 1. A first rotating member and a second rotating member are coaxially arranged, and the first rotating member is located at a position where the first rotating member and the second rotating member come into close proximity to each other. On the member side, there is provided a permanent magnet that allows a magnetic flux to flow into the second rotating member side, attracts the second rotating member, and enables the first rotating member and the second rotating member to rotate integrally. On the other hand, on the side where the second rotating member is disposed, a magnetic flux is caused to flow into the second rotating member and the attraction force of the permanent magnet is adjusted to allow the first rotating member and the second rotating member to move together. A DC excitation coil that enables relative rotation is fixedly arranged, and furthermore, between the second rotating member side and the exciting coil side in the magnetic flux path of the permanent magnet and the exciting coil in the second rotating member. The air gap changes periodically with the rotation of the second rotating member. A rotation speed detecting device, comprising: a rotation surface; and counting a frequency of a sine-wave-like induced voltage generated in the excitation coil. 2. The rotational speed detection device according to claim 1, wherein the rotating surface of the second rotating member is provided at a position close to the permanent magnet on a magnetic flux path of the permanent magnet. apparatus. 3. The second rotating member according to claim 1, wherein the rotating surface of the second rotating member is formed in a circumferential direction of the second rotating member, and one of radial directions of the second rotating member. A rotation speed detecting device, wherein the permanent magnet is arranged on one side and the exciting coil is arranged on the other side. 4. The rotating member according to claim 1, wherein the rotating surface of the second rotating member is formed in a radial direction of the second rotating member, and the second rotating member is formed with respect to the rotating surface. Wherein the permanent magnet and the exciting coil are provided on one side in the axial direction of the rotational speed detector. 5. The magnetic flux of claim 1, wherein the direction of the magnetic flux of the exciting coil is the same as that of the magnetic flux of the permanent magnet at a position where the first rotating member and the second rotating member are close to each other. A rotation speed detecting device, which is set so as to be in the same direction as a direction of a magnetic flux returning to the permanent magnet through only the second rotating member. 6. The auxiliary permanent magnet according to claim 5, wherein an auxiliary permanent magnet is provided at a yoke portion of the excitation coil, and a magnetic flux direction of the auxiliary permanent magnet is set to be the same as a magnetic flux direction of the excitation coil. A rotation speed detecting device, wherein the magnetic force is set to be larger than the magnetic force of the magnetic flux of the permanent magnet flowing into the yoke side of the exciting coil by a predetermined value. 7. A first rotating member and a second rotating member are coaxially arranged, and the first rotating member is located at a position where the first rotating member and the second rotating member come close to and face each other. On the member side, there is provided a permanent magnet that allows a magnetic flux to flow into the second rotating member side, attracts the second rotating member, and enables the first rotating member and the second rotating member to rotate integrally. On the other hand, on the side where the second rotating member is disposed, a magnetic flux is generated by the second rotating member to adjust the attraction force of the permanent magnet, and the relative position between the first rotating member and the second rotating member is adjusted. A DC excitation coil that enables rotation is fixedly arranged, and an air gap between the permanent magnet and the excitation coil in the second rotating member and the excitation coil side periodically changes with rotation. To provide a sinusoidal wave generated in the excitation coil. A rotational speed detecting device configured to detect the rotational speed of the second rotating member by counting the frequency of the conductive pressure is attached to each of an intake side camshaft and an exhaust side camshaft of an engine. A valve timing detection device configured to detect a timing, wherein one of the intake-side camshaft and the exhaust-side camshaft is provided with a cylinder determination unit, and the valve timing detection device corresponds to a camshaft provided with the cylinder determination unit. The rotation number detecting device has the camshaft connected to the first rotation member, and the cylinder number identification device corresponds to a camshaft not provided with the cylinder discrimination.
A valve timing detecting device, wherein the valve timing detecting device is connected to a rotating member. 8. A first rotating member and a second rotating member are coaxially arranged, and the first rotating member is located at a position where the first rotating member and the second rotating member come into close proximity to each other. On the member side, there is provided a permanent magnet that allows a magnetic flux to flow into the second rotating member side, attracts the second rotating member, and enables the first rotating member and the second rotating member to rotate integrally. On the other hand, on the side where the second rotating member is disposed, a magnetic flux is generated by the second rotating member to adjust the attraction force of the permanent magnet, and the relative position between the first rotating member and the second rotating member is adjusted. A DC excitation coil that enables rotation is fixedly arranged, and an air gap between the permanent magnet and the excitation coil in the second rotating member and the excitation coil side periodically changes with rotation. To provide a sinusoidal wave generated in the excitation coil. A valve timing detecting device configured to detect a valve timing by assembling a rotational speed detecting device configured to detect a rotational speed of the second rotating member by counting a frequency of a conductive pressure to a camshaft of an engine; A valve timing detecting device, wherein a cylinder discriminating means is provided on a crankshaft of an engine, and wherein the camshaft is connected to a second rotating member of the rotational speed detecting device.