JPH0411807A - Set position-stopping clutch - Google Patents

Abstract

PURPOSE:To enhance precision of stopping position by forming a cam face for suppressing rotation having upward inclination and engaged to a drawing pin more backward than a rotation phase part, in which a forced cam face of a driven rotator which engages and detaches to a driving rotator is formed, in a specific position. CONSTITUTION:A cam face 33 for suppressing rotation having upward inclina tion is formed on a spiral cam face 30 having upward inclination and capable of subjecting a driven rotator 26 to forced slide displacement against a spring in clutch-off direction. When a drawing pin acts on a forced cam phase 32 and a clutch is turned off, the drawing pin is situated at the lower position of the cam face and the driven rotator stops at a clutch-off position without continuing rotation by the force of inertia.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fixed position stop clutch that can stop a working device at a constant rotational phase.

[Conventional technology]

For example, it is desirable that the clutch built into the transmission system for the planting device of a rice transplanter (planting clutch) be disengaged when the planting claw is raised to a predetermined position above the rice field. As an example, Jikoko Sho 62-2881
The one disclosed in Publication No. 2 is known.

This known clutch includes a driving rotor, a driven rotor that engages and disengages from the drive rotor by sliding in the direction of the rotation axis, and a clutch that slides and urges the driven rotor toward the occlusal side. The driven rotor includes a spring and a restraining pin for clutch operation that advances and retreats from a radial direction within the rotation locus of the driven rotary body, and the driven rotary body moves in a fixed direction when engaged with the restraining pin whose position is fixed. By rotating the driven rotor to , an upwardly inclined helical cam surface is formed that forces the driven rotor to slide in the clutch disengaging direction against the spring, and the checker is provided at the rear of the helical cam surface. It is constructed with a push-in cam surface that slides the driven rotor to the fully clutch disengaged position by pushing the pin toward the center of the driven rotor, and the operation is as easy as pushing the check pin toward the driven rotor. It has the characteristic that the clutch can be easily disengaged with force.

In this clutch, the clutch is in a disengaged state in which the restraining pin (hawk member in the publication) is pushed in and acts on the cam surface (second cam surface in the publication) to completely separate from the drive rotating body (drive side member in the publication). The driven rotor further rotates due to inertia, and the stopper surface provided thereon collides with a restraining pin fixed in position, thereby stopping the driven rotor at a constant rotational phase.

[Problem to be solved by the invention]

However, the fixed-position stopping clutch with the conventional configuration described above utilizes the phenomenon that the driven rotor rotates due to inertia after being completely disengaged to stop the fixed-position clutch. If the resistance increases due to poor lubrication, friction between members, etc., there is a risk that the inertial rotational force will be insufficient and the driven rotating body will stop before the stopper surface collides with the check pin. In addition, in order to make the stopper surface come into contact with the check pin even with a small inertial rotational force, if the stopper surface is formed close to the rear of the push-in cam surface forming part, which is the complete clutch disengagement phase, the stopper surface will be strong when the inertial force is large. When the rotor collides with the check pin, the driven rotor rotates in reverse due to the reaction, and there is a risk that the stop position may shift.In any case, there is a drawback that an error in the stop position occurs due to a change in the inertial rotational force.

The object of the present invention is to improve the stopping position accuracy of this type of fixed position stopping clutch.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a driving rotating body;
A driven rotary body that engages and disengages from the driving rotary body by sliding in the direction of the rotational axis, a clutch engagement spring that biases the driven rotary body to slide toward the occlusal side, and a rotation locus of the driven rotary body. and a restraining pin for clutch operation that moves forward and backward in the radial direction, and the driven rotating body rotates in a fixed direction while being engaged with the restraining pin whose position is fixed, thereby causing the driven rotating body to rotate. An upwardly inclined helical cam surface is formed to force a sliding displacement in the clutch disengaging direction relatively against the spring, and at the rear part of this helical cam surface, the restraining pin is pushed toward the center of the driven rotating body. In a fixed position stop clutch that is provided with a push-in cam surface that slides the driven rotor to a fully clutch disengaged position, the check-in position that has been pushed is located behind the rotational phase portion on which the push-in cam surface is formed. An upwardly inclined rotation suppressing cam surface that engages with the pin is formed so as to be connected to the spiral cam surface.

[For production]

According to the configuration of the present invention, when the check pin acts on the pushing cam surface and the clutch is completely disengaged, the check pin is located at a lower position of the rotation suppressing cam surface formed on the driven rotor, and the driven rotor is In order to continue rotating due to inertia, it is necessary for the check pin to relatively climb up this upwardly inclined rotation-suppressing cam surface, and this acts as resistance, causing the driven rotor to engage the cam surface and check pin. It will stop at the fully clutch disengaged position.

In this case, by applying an external force greater than the overcoming resistance to the rotation suppressing cam surface to the stopped driven rotary body, it is possible to forcibly manually rotate the driven rotary body, that is, the working device interlocked therewith.

The distal end engaging portion of the restraining pin is formed into a tapered cone shape, and the spiral cam surface, the pushing cam surface and the rotation suppressing cam surface are formed around the outer peripheral surface of the distal end engaging portion. When the slanted surface is formed at an inclined angle, the restraining pin contacts each cam surface in a line or surface, improving durability.

Further, if a parallel cam surface is formed along the circumferential direction from the terminal end of the rotation-suppressing cam surface to allow manual rotation of the driven rotor, the working device can be rotated forward by hand after stopping at a fixed position. can be performed without requiring particularly large force.

〔Effect of the invention〕

As described above, according to the present invention, the driven rotating body can be stopped at a constant rotational 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 based on 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 transmission case (2) at the front, and a pair of left and right propulsion wheels (3).
A planting case (5) and 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 (9) for leveling the ground and a pair of left and right side floats (10) are installed at the bottom of the fuselage. Fig. 1 shows the seedling device (8).
) and the transmission structure of the planting device are shown in FIG.

As shown in Fig. 7, the planting case (5) includes a central planting case (5a) that drives the seedling planting mechanism (6) in the two central rows, and a left and right pair that drives the two outer rows, respectively. The central planting case (5a) is connected to the side planting case (5b) by a pipe frame (5C), and the central planting case (5a) is connected to the side planting case (5b) from the mission case (2) to the rear, as shown in Fig. 1. It is connected to the rear end of the extended main pipe frame (11) which also serves as a transmission case, and a seedling stand driving case (12) is connected to the upper part of the central planting case (5a).

As shown in Fig. 1, a transmission shaft (13) that receives engine power is inserted into the main pipe frame (11), and the rear end of this transmission shaft (13) and the central planting case (5a
) is interlocked with the input shaft (14) supported at the front part of the planter (14) via a jump clutch type safety clutch (15), and this input shaft (14) and the planting drive shaft (
16) are interlocked and connected via a bevel gear (17) and a fixed position stop clutch (18) as a planting clutch.

The power transmitted to this planting drive shaft (16) is
The transmission is branched 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. Further, the power of the central planting drive shaft (16) is transmitted to the seedling stand drive case (12) to drive the screw shaft (23) for horizontally feeding the seedling stand.

The fixed position stop clutch (18) as a planting clutch
is a position where the seedling planting mechanism (6) is moved significantly upwards from the field surface, specifically at the bottom end of the seedling platform, when the operation lever (24) provided in the control section at the rear of the machine is operated. A function of stopping at a predetermined position slightly before entering the seedling removal port is required, and in the present invention, this fixed position stopping 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 engaged with the bevel gear (17) and is loosely fitted to the planting drive shaft (16) with a constant position in the axial direction, and a planting drive! (16) A driven rotor (26) with a spline that allows it to slide freely
and a claw (
25a) The entire seedling planting device (8) is driven and stopped by engaging and disengaging the nail (26a) formed on the end face of the driven rotor (16).

The driven rotary body (16) is biased to slide toward the claw engagement side, that is, the clutch engagement side, by a spring (27), and is in contact with the check pin (28) that advances and retreats from the center planting case (5a) in the radial direction. Due to the cam action caused by engagement, the spring (27)
It is designed to be forcibly displaced backwards against the

A clutch disengagement 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 rotor (26), a parallel cam surface (29) that allows the restraining pin (28) to engage is provided along the circumferential direction within a predetermined phase range. (θ1), and after the rotation of this parallel cam surface (29), an upwardly inclined spiral cam surface (30) is formed within a predetermined phase range (θ2).
), and these parallel cam surfaces (29
) and a check pin (
A peripheral wall surface <31) is formed which abuts and supports the tip of 28).

Further, the peripheral wall surface (31) ends at the rotational phase portion (A) corresponding to the rear end of the helical cam surface (30), and the check pin (28) is allowed to advance toward the rotation axis side. Helical cam surface (30) at this rotational phase portion (A)
In order to displace the driven rotor (26) away from the drive rotor (25) (clutch disengagement direction) by advancing the check pin (28) at a location closer to the rotation axis, the rotation axis is raised higher. A set pushing cam surface (32) is formed.

Further, behind the rotational phase portion (A), there is an upwardly inclined rotation suppressing cam surface (30) following the spiral cam surface (30).
3) is formed over a certain small range (θ3).

A parallel cam surface (34) along the circumferential direction is formed behind the rotation suppressing cam surface (33) over a certain phase range (θ,), and a contact surface (35) is formed at the end of the parallel cam surface (34).
) are erectly formed.

The distal end engaging portion (28a) of the check pin (28) is formed into a tapered cone shape, and each of the cams (29), (30), (32), (3-
3) and (34) are formed into inclined surfaces 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 explained.

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 advancing spring (37). The driven rotating body (2
6) is biased and engaged with the drive rotating body (25) by a spring (27).

When the operating lever (24) is operated to the clutch disengaged position,
The release wire (36) is loosened and the check pin (28)
is advanced into the rotation locus of the driven rotor (26) by the spring (37).

The advanced check pin (28) first enters the parallel cam 29) in the phase range (θI), and its tip touches the peripheral wall surface (
31) Uke is stopped.

As the driven rotor (26) rotates, the check pin (28) enters a relative rotational phase (θ2) and engages with the upwardly inclined helical cam surface (30). As the helical cam surface (30) rotates with respect to the restraining pin (28) which is fixed in position, the driven rotary body (26) is relatively slid in a direction away from the drive rotary body (25).

When the check pin (28) relatively reaches the rotational phase portion (A), the peripheral wall surface (31) disappears, the check pin (28) is pushed toward the rotation axis by the spring (37), and the push cam surface ( 32), the driven rotating body (26) is further slid in the direction away from the driving rotating body (25), and the claw (
25a), (26a) A comrade leaves. In other words, a completely unlatched state is brought about.

In this case, the driven rotary body (26) whose transmission is cut off tries to rotate further due to the inertia based on the mass of various parts linked to it, but the rotational phase portion (A) which is the clutch disengagement phase At the rear is an upwardly sloping rotation suppressing cam surface (33
) exists and provides resistance to prevent inertial rotation, so the driven rotating body (26) stops at this rotational phase position (A).

At this time, the seedling planting device (6) is in the state shown in FIG.

In addition, in this fixed position stop state, the seedling planting mechanism (6
), the check pin (28) relatively rides on the parallel cam surface (34), and from then on the check pin (28) rides on the parallel cam surface (34).
The driven rotor (26) can be rotated forward with little resistance until the contact surface (35) comes into contact with the seedling platform (7), and the tip of the planting claw (6a) of the seedling planting mechanism (6) ) can be easily rotated by hand when approaching the gauge block set in the lower end outlet (7a).

And each cam surface (29), (30) as mentioned above.

(32), (33) and (34) are check pins (28)
Since the contact when engaging and sliding comes into contact with a line along the outer peripheral surface of the tapered cone, it has high durability against friction.

In addition, the check pin (28) may be a straight pin,
In this case, only the push-in cam surface (32) is an inclined surface that is higher on the rotation axis side.

Note that although symbols are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of drawings]

The drawings show an embodiment of the fixed position stopping clutch according to the present invention, in which Fig. 1 is a cross-sectional plan view of the main part of the transmission part, Fig. 2 is a side view of the main part showing the fixed position stopped state, and Fig. 3 is the clutch. 4 is a side view thereof, FIG. 5 is a front view thereof, FIG. 6 is a developed side view of its cam surface, and FIG. 7 is a transmission structure of the seedling planting device. FIG. 8 is an overall side view of the walking rice transplanter. (25)... Drive rotating body, (26)...
・Followed rotating body, (27)...Spring, (28)・
...Restraint pin, (30) ... River/screw cam surface, (
32)...Press cam surface, (33)...
- Rotation suppressing cam surface, (34)...Parallel cam surface, (35)...Abutment surface, (A)...Rotation phase portion.

Claims (1)

[Scope of Claims] 1. A driving rotating body (25), a driven rotating body (26) that engages and disengages from the driving rotating body (25) by sliding in the direction of the rotation axis, and this driven rotating body (26). ) for sliding into the occlusal side (27);
The driven rotor (26) is provided with a check pin (28) for clutch operation that advances and retreats in the radial direction within the rotation locus of the driven rotor (26), and the driven rotor (26) is provided with the check pin (28) whose position is fixed.
28), the driven rotor (26) rotates in a certain direction, thereby forcing the driven rotor (26) to relatively slide in the clutch disengagement direction against the spring (27). A spiral cam surface (30) with an upward slope is formed, and a rear portion of the spiral cam surface (30) has a
In the fixed position stop clutch, the fixed position stop clutch is provided with a pushing cam surface (32) that slides the driven rotating body (26) to a completely clutch disengaged position by pushing the check pin (28) toward the center of the driven rotating body. Behind the rotational phase part (A) on which the push-in cam surface (32) is formed, an upwardly inclined rotation suppressing cam surface (33) that engages with the push-operated check pin (28) is provided in the spiral direction. Cam surface (
30). 2. The distal end engaging portion (28a) of the check pin (28) is formed into a tapered cone shape, and the spiral cam surface (30), the pushing cam surface (32), and the rotation suppressing cam surface ( 33) to the tip engaging portion (28).
2. The fixed position stop clutch according to claim 1, wherein the fixed position stop clutch is configured to have an inclined surface having the same inclination angle along the outer circumferential surface of (a). 3. To the rear from the end of the rotation suppressing cam surface (33),
3. The fixed position stop clutch according to claim 1, further comprising a parallel cam surface (34) formed along the circumferential direction to allow manual rotation of the driven rotor (26). 4. Attach the check pin (2) to the terminal end of the parallel cam surface (34).
4. The fixed position stop clutch according to claim 3, wherein the abutment surface (35) for limiting the hand rotation range acting on the rotation range is formed in an upright manner.