JP2566040B2 - Fixed position stop clutch - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a fixed position stop clutch capable of stopping a work position at a constant rotational phase.

[Conventional technology]

For example, it is desirable that a clutch (planting clutch) incorporated in a power transmission system for a planting device of a rice transplanter be disengaged in a state where the planting claw is raised to a predetermined position above the rice field, and a clutch having such a function is provided. As one example, the one disclosed in Japanese Utility Model Publication No. 62-28812 is known.

This known clutch includes a drive rotating body, a driven rotating body that is engaged with and disengaged from the drive rotating body by sliding movement in the direction of the rotation axis, and a clutch for energizing the driven rotating body to slide on the occlusal side. A spring and a check pin for clutch operation that moves forward and backward in a radial direction within a rotation locus of the driven rotary body are provided, and the driven rotary body has a fixed direction in which the driven rotary body is engaged in a state of engagement with the check pin that is fixed in position. By rotating the driven rotary body against the spring, the spiral cam surface is formed so as to forcibly slide and displace in the clutch disengagement direction, and at the rear portion of the spiral cam surface, the restraint is provided. It is configured by providing a pushing cam surface for slidingly displacing the driven rotating body to the complete clutch disengagement position by pushing displacement of the pin toward the center of the driven rotating body. With a light operating force enough to advance to the dynamic rotary section, it has a feature that can be lightly perform clutch disengaging operation.

In this clutch, the clutch disengaged state in which the check pin (Hawk member of the publication) is acted on the pushing cam surface (the first cam surface of the publication) to completely disengage it from the driving rotor (the driving side member of the publication) Then, the driven rotary body further rotates due to inertia, and the stopper surface provided on the driven rotary body collides with the check pin for fixing the position, whereby the driven rotary body is stopped in a constant rotation phase. That is, it is configured to move the range of existence of the parallel cam surface (second cam surface of the publication), which is provided subsequent to the pushing cam surface, for permitting the manual rotation operation by inertial rotation of the driven body. .

[Problems to be Solved by the Invention]

However, since the fixed position stop clutch of the above-mentioned conventional structure is used to perform a fixed position stop by utilizing the phenomenon that the driven rotating body rotates due to inertia after complete disengagement, the fixed side stop clutch on the driven side does not When the resistance is increased due to poor lubrication or friction of members, the inertial rotational force is insufficient, and the driven rotor may stop before the stopper surface abuts against the check pin. Also, in order to make the stopper surface collide with the check pin even with a small inertial rotation force, if the stopper surface is formed close to the rear of the pushing cam surface forming part which is the clutch full disengagement phase, the stopper surface is strong when the inertia force is large. In addition, there is a possibility that the driven rotor will reversely rotate due to the collision with the restraint pin and the stop position will shift, and in any case, there will be an error in that the stop position will have an error due to a change in the inertial rotational force.

It is an object of the invention to improve the stop position accuracy of such a type of fixed position stop clutch.

[Means for solving the problem]

In order to achieve the above-mentioned object, the present invention provides a drive rotating body, a driven rotating body that is engaged with and disengaged from the drive rotating body by a sliding movement in the direction of the rotation axis, and a driven rotating body that slides on the occlusal side. A spring for energizing the clutch, and a check pin for clutch operation for advancing and retracting from the radial direction within the rotation locus of the driven rotating body, and the driven rotating body,
The driven rotary body rotates in a fixed direction in an engaged state with the check pin that is fixed in position, so that the driven rotary body is forcedly slid in the clutch disengaging direction relatively against the spring, whereby the spiral cam is inclined upward. A surface is formed, and the driven rotor is slid to the complete clutch disengagement position by pushing the check pin toward the center of the driven rotor at the lower side portion of the spiral cam surface in the rotation direction in the certain direction. A pushing cam surface is provided, and a parallel cam surface that allows manual rotation of the driven rotating body in the clutch disengaged state is formed in the circumferential direction at the lower side of the pushing cam surface in the direction of rotation in the fixed direction. In the fixed-position stop clutch that is provided, it is on the rotation direction lower side than the rotation phase portion on which the pushing cam surface is formed and on the rotation direction upper side than the parallel cam surface. The position, the rotation suppression cam surface of the up-ramp for engaging the restraining pin which is pushed is formed by continuously to the helical cam surface.

[Work]

According to the configuration of the present invention, in the state where the check pin acts on the pushing cam surface and is in the complete clutch disengaged state, the check pin is located at a lower position of the rotation suppressing cam surface formed on the driven rotating body, and the driven rotating body is In order to continue rotation due to inertia, the check pin must relatively climb up the rotation-suppressing cam surface for restraint, and this acts as resistance and the driven rotor engages the push-in cam surface and the check pin. It will stop at the complete clutch disengagement position.

In this case, if an external force larger than the resistance to jump over the rotation suppressing cam surface is applied to the stopped driven rotating body, the driven driven rotating body, that is, the working device linked to the driven rotating body can be manually rotated.

Further, since a parallel cam surface that allows manual rotation of the driven rotating body is formed along the circumferential direction on the lower side in the rotation direction from the end of the rotation suppressing cam surface, after stopping at a fixed position. Therefore, the working device can be rotated by hand rotation without requiring a particularly large force.

The tip engaging portion of the check pin is formed in a tapered tapered cone shape, and the spiral cam surface, the pushing cam surface, the rotation suppressing cam surface, and the parallel cam surface are
When the outer peripheral surface of the tip engaging portion is formed as an inclined surface having the same inclination angle around the circumference, the check pin comes into line contact with each cam surface, or comes into contact with each cam surface to improve durability.

〔The invention's effect〕

As described above, according to the present invention, it is possible to stop the driven rotating body at a constant rotation phase with high accuracy regardless of the magnitude of the inertial force at the time of clutch disengagement.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 8 shows an overall side view of a walk-behind rice transplanter which is an example of a working machine equipped with the fixed-position stop clutch of the present invention.

This walk-behind rice transplanter is equipped with an engine (1) and a mission case (2) in the front part and is configured to run on a pair of left and right propulsion wheels (3) at the rear part of a walk-behind self-propelled vehicle (4). A planting case (5), four sets of crank-type seedling planting mechanisms (6), a seedling planting device (8) consisting of a seedling stand (7), etc. are connected, and a center float for leveling is provided at the bottom of the machine. (9) and a pair of left and right side floats (10)
FIG. 1 shows an input section to the seedling attaching device (8), and FIG. 7 shows a transmission structure of the planting device.

The planting case (5) is, as shown in FIG. 7, a central planting case (5a) for driving the central two-row seedling planting mechanism (6).
And a pair of left and right side planting cases (5b) that respectively drive the two outer rows are connected by a pipe frame (5c), and this central planting case (5a) is shown in FIG. As shown, it is connected to the rear end of the main pipe frame (11) that also extends backward from the mission case (2) and also serves as a transmission case, and drives the seedling stand on top of the central planting case (5a). The case (12) is connected.

As shown in FIG. 1, a transmission shaft (13) for receiving engine power is inserted in the main pipe frame (11).
The rear end of this transmission shaft (13) and the input shaft (14) supported on the front part of the central planting case (5a) are interlockingly connected through a jump clutch type safety clutch (15), and The input shaft (14) and the central two-row planting drive shaft (16) are interlockingly coupled via a bevel gear (17) and a fixed position stop clutch (18) as a planting clutch.

Then, the power transmitted to the planted drive shaft (16) is
It is branched and transmitted to the planting drive shaft (22) of the side planting case (5b) via the chain (19), the intermediate transmission shaft (20) in the pipe frame (5c) and the chain (21). There is. The power of the central planting drive shaft (16) is transmitted to the seedling stand driving case (12) to drive the screw shaft (23) for lateral feeding of the seedling supporting stand.

The fixed position stop clutch (18) as a planting clutch
Is the position where the seedling planting mechanism (6) has been moved significantly upward from the paddy field when it is cut and operated by the operation lever (24) provided on the control section at the rear of the aircraft, specifically, at the lower end of the seedling stand. It is required to have a function of stopping at a predetermined position just before entering the seedling take-out port. In the present invention, the fixed position stop clutch (18) is configured as follows.

As shown in FIG. 1, this fixed position stop clutch (18)
Is a drive rotating body (25) with a bevel gear part that is always meshed with the bevel gear (17) and is loosely fitted to the planted drive shaft (16) in a state where the axial center position is fixed, and the planted drive shaft (16). It consists of a driven rotor (26) slidable outside the spline, and a pawl (25a) formed on the end face of the drive rotor (25) and a pawl (26a) formed on the end face of the driven rotor (16). The whole of the seedling planting device (8) is driven and stopped by being engaged and disengaged.

The driven rotating body (16) is urged to slide by the spring (27) toward the pawl engaging side, that is, the clutch engaged side,
A cam action by engagement with a check pin (28) that advances and retreats from the central planting case (5a) in the radial direction is forcibly retracted and displaced against the spring (27).

A clutch disengaging cam that acts on the check pin (28) is formed as follows. As shown in FIGS. 3 to 6, near the outer periphery of the driven rotary body (26), a parallel cam (29) which allows the check pin (28) to be engaged is arranged in a predetermined phase range ( formed over θ ₁ ) and
A spiral cam surface (30) having an upward slope is formed over a predetermined phase range (θ ₂ ) following the rotation of the parallel cam surface (29), and the parallel cam surface (29) and the spiral cam surface (30) are formed. A peripheral wall surface (31) for supporting the tip of the check pin (28) in abutment is formed on the rotation axis side of (30).

Further, the peripheral wall surface (31) ends at the rotation phase portion (A) corresponding to the rear end of the spiral cam surface (30), and the check pin (28) is allowed to advance toward the rotation axis. A direction in which the driven rotary body (26) is separated from the drive rotary body (25) by advancing the check pin (28) at a location on the rotary shaft side of the spiral cam surface (30) in the rotary phase portion (A) ( A push-in cam surface (32) is formed with its rotation axis side set high for displacement in the clutch disengagement direction).

Further, the rotation suppressing cam surface (33) following the spiral cam surface (30) on the lower side of the rotation phase portion (A) in the rotation direction at the time of clutch disengagement operation has a certain small range (θ).
₃ ) is formed.

A parallel cam surface (34) along the circumferential direction is formed behind the rotation suppressing cam surface (33) over a constant phase range (θ ₄ ), and a contact surface (35) is formed upright at the end thereof. Has been done.

Further, the tip engaging portion (28a) of the restraining pin (28) is formed in a tapered taper cone shape, and the cams (29), (30), (32), (33) and (34) are formed. ) Is an inclined surface having the same inclination angle along the outer peripheral surface of the tip engaging portion (28a).

Next, the operation of the fixed position stop clutch (18) will be described.

When the operating lever (24) is in the clutch engaged position, the check pin (28) linked to the lever (24) via the release wire (36) is driven against the advance biasing spring (37). The driven rotating body (26) which is retracted out of the rotation locus of the rotating body (26) and is not restrained by the restraining pin (28) is a spring (2
It is urged and occluded by the drive rotor (25) by 7).

When operating the operating lever (24) to the clutch disengagement position,
The release wire (36) is loosened and the restraining pin (28) advances into the rotation locus of the driven rotating body (26) by the spring (37).

The check pin (28) that has advanced advances into the parallel cam (29) in the phase range (θ ₁ ) _first , and its tip ends on the peripheral wall surface (3
Taken in 1).

With the rotation of the driven rotor (26), the check pin (28) relatively enters the rotational phase (θ ₂ ) and engages with the upwardly inclined spiral cam surface (30). As the spiral cam surface (30) rotates with respect to the restraining pin (28) whose position is fixed, the driven rotor (2
6) is relatively slid in the direction away from the drive rotor (25).

When the check pin (28) relatively reaches the rotational phase portion (A), the peripheral wall surface (31) disappears and the check pin (28) is pushed toward the rotation axis by the spring (37), and the pushing cam surface ( The driven rotating body (26) is further slid in the direction away from the driving rotating body (25) by the action of 32), and the claws (25a),
(26a) Separate from each other. That is, a completely disengaged state is brought about.

In this case, the driven rotary body (26) whose transmission has been cut off tries to further idle due to the inertia based on the mass of various parts linked thereto, but the rotation phase portion (A) which is the clutch disengagement phase. On the lower side in the rotation direction, there is a cam surface (33) for upward rotation, which suppresses inertial rotation, so that the driven rotating body (26) has a rotation phase portion (A). Stop. At this time, the seedling planting device (6) is the second
It is in the state shown in the figure.

Further, in this fixed position stopped state, the seedling planting mechanism (6) is provided with a force that overcomes the rotation resistance of the rotation suppressing cam surface (33).
When the handwheel is operated, the restraint pin (28) relatively climbs up on the parallel cam surface (34), and thereafter, the resistance is low until the contact surface (35) contacts the restraint pin (28), and the driven rotating body (26).
Can be rotated forward and the tip of the planting claw (6a) of the seedling planting mechanism (6) can be easily rotated when brought close to the gauge block set in the lower end outlet (7a) of the seedling stand (7). You can do it.

Then, as described above, each cam surface (29), (30), (3
When the sliding pins (28), (2), (33) and (34) are in sliding contact with each other, the contact is line contact along the outer peripheral surface of the taper cone, and therefore the durability against friction is high.

The restraint pin (28) may be a straight pin,
In this case, only the pushing cam surface (32) has a high inclined surface on the rotation axis side.

It should be noted that although symbols are added to the claims for convenience of comparison with the drawings, the present invention is not limited to the structure of the accompanying drawings by the entry.

[Brief description of drawings]

The drawings show an embodiment of a fixed-position stop clutch according to the present invention. Fig. 1 is a cross-sectional plan view of a main part of a transmission portion, Fig. 2 is a side view of the main part showing a fixed-position stopped state, and Fig. 3 is a clutch. 4 is a side view thereof, FIG. 5 is a front view thereof, and FIG. 6 is a developed side view of a cam surface thereof.
The figure shows the front elevational view showing the transmission structure of the seedling planting equipment, No. 8
The figure is an overall side view of the walk-behind rice transplanter. (25) …… Drive rotor, (26) …… Driven rotor, (27)
...... Spring, (28) …… Control pin, (30) …… Spiral cam surface, (32) …… Pushing cam surface, (33) …… Rotation suppression cam surface, (34) …… Parallel cam surface, (35) …… For the time being,
(A) ... Rotation phase part.

Claims (3)

(57) [Claims] 1. A drive rotating body (25), a driven rotating body (26) which is engaged with and disengaged from the drive rotating body (25) by sliding movement in the direction of the rotation axis, and the driven rotating body (26) is engaged with the driven rotating body (26). The driven rotating body is provided with a clutch-engaging spring (27) for slidingly biasing the driven side, and a clutch operation restraining pin (28) moving forward and backward in a radial direction within a rotation locus of the driven rotating body (26). The driven rotating body (26) is rotated in a certain direction in an engaged state with the check pin (28) whose position is fixed, so that the driven rotating body (26) relatively moves to the spring (26). 2
7) A spiral cam surface (30) with an upward inclination is formed to forcibly slide and displace in the clutch disengagement direction against 7), and at the same time the spiral cam surface (30) is rotated downward in the certain direction, the check restraint is provided. A pushing cam surface (32) for slidingly displacing the driven rotating body (26) to the completely clutch disengaged position by pushing displacement of the pin (28) toward the center of the driven rotating body is provided, and from this pushing cam surface (32) Also on the lower side portion in the direction of rotation in the fixed direction, a parallel cam surface (3) that allows manual rotation of the driven rotating body (26) in the clutch disengaged state.
In a fixed position stop clutch in which 4) is formed along the circumferential direction, the parallel cam surface () is located on the rotation direction lower side than the rotation phase portion (A) on which the pushing cam surface (32) is formed. A rotation suppressing cam surface (33) which engages with the check pin (28) that has been pushed in is connected to the spiral cam surface (30) at a position on the rotation direction upper side than that of 34). A fixed-position stop clutch characterized by being formed. 2. A tip engaging portion (28) of the check pin (28).
a) is formed into a tapered cone shape,
The spiral cam surface (30), the pushing cam surface (32), the rotation suppressing cam surface (33), and the parallel cam surface (34) have the same inclination angle along the outer peripheral surface of the tip engaging portion (28a). The fixed-position stop clutch according to claim 1, wherein the fixed-position stop clutch is formed as an inclined surface. 3. A fixed position stop according to claim 1, wherein a contact surface (35) for limiting a hand-turning range that acts on the check pin (28) is formed upright at the end of the parallel cam surface (34). clutch.