JP2001191198A - Motor-driven guide pin clamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor-driven guide pin clamp having a new combination mechanism between a guide pin and a clamp pawl taking a dust seal into consideration. SOLUTION: The clamp pawl is advanced and retreated by dividing a conventional guide pin into two parts orthogonally to the axis and rotating the tip end part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[Industrial application] It is used for positioning and holding a work in factory equipment for welding sheet metal and the like.

2. Description of the Related Art A guide pin clamp using an air cylinder, in which a slit is formed in a fixed guide pin, and the slit moves in and out of the slit in a direction perpendicular to the axis when a clamp claw moves in the axial direction.

[Problems to be Solved by the Invention] In the clamp according to the prior art, there is a possibility that spatters or the like at the time of welding may enter the slit portion and cause a defect. , No dust seal. An object of the present invention is to solve the problem of the dust seal and the energy saving by electrically driving the pneumatic drive.

[Means for Solving the Problems] A guide pin is divided at a cross section perpendicular to an axis, and the divided surface is used as a sliding surface between the two. Do.

[Embodiment of the Invention] A description will be given with reference to the drawings. FIG. 1 is an axial sectional view of the present invention using a true circular type guide pin. FIG. 2 is a plan view showing a sliding surface of a guide pin and a clamp claw when a true circular type clamp is performed. FIG. 3 is a plan view showing a sliding surface of a guide pin and a clamp claw when an elliptical type clamp is performed. FIG. 4 is a cross-sectional view taken along a line AB in FIG. FIG. 5 is an assembly view of a cylindrical coil spring and a retainer used in the present invention. In FIG. 1, a guide pin 1 and a clamp claw 2
The sliding surfaces 7 and 8 are perfect circles of the same shape, and the guide pin 1 is provided with an eccentric hole 9 at an eccentric position, and the same eccentric amount is provided at the tip of the clamp rod 3 fitted with the eccentric hole 9. The clamp claw 2 is fixed. A guide groove 10 for preventing rotation is formed in the large diameter portion of the guide pin 1.
Further, stoppers 5 and 6 are provided on the other end surface of the guide pin 1 and the end surface of the stopper member 11 so that they can be relatively rotated by 180 degrees. next,
The assembly of the main part of the present invention will be described. Guide pin 1
The clamp rod 3 to which the clamp claw 2 is fixed is passed through the eccentric hole 9 of the above. Then, the thrust bearing 12 and the stopper member 11 are brought into contact with the end surface 7 of the guide pin 1 and the end surface of the clamp claw 8 (contact). Through to a certain position, and
The stopper member 11 is fixed to the clamp rod 3 with the set screw 13 in a state where the sliding surfaces coincide (the perfect circles completely overlap) at the position where the stopper 5 and the stopper 6 abut. In this state, the finite rotation (18) between the guide pin 1 and the clamp rod according to claim 1 is performed.
0 degree), and the sliding surface between the end surface of the guide pin and the end surface of the clamp claw is achieved. Next, the principle of the rotation / linear conversion mechanism used in the present invention is that the rotation of the shaft 21 is stopped, and when the thin cylindrical member 22 is rotated by the electric motor, the shaft 21 linearly moves in the axial direction. , The clamp rod 3 and the shaft 21 are fixed via the stopper member 11 by the frictional force caused by the flat spring force, and the detent groove provided in the large diameter portion of the guide pin 1 and the rotation fixed to the cap 27. Since the guide pin 1 does not rotate due to the stop pin 4, the clamp rod 3 moves in the axial direction after rotating by 180 degrees.
Next, the rotation linear conversion mechanism used in the present invention will be described in detail. In FIG. 1, the thin cylindrical member 22 is fixed to the outer periphery of the rotating member 32 by driving and caulking. The thickness of the thin cylindrical member 22 is processed so that both ends are thickened. A rotating member 32 attached to a bearing case 36 with two ball bearings 34 and nuts 36 constrained in the axial direction is connected to a shaft 31 of the electric motor. A confirmation magnet 18 and a thrust bearing 16 are fixed to the stopper member 11 fixed to the clamp rod 3. The clamp rod 3 is attached by a round nut 30 via the spring force of a flat spring 39. In FIG. 4, eight linear retainer pins 2 are inserted into eight cylindrical coil springs 23.
9 is passed. In FIG. 5, both ends of the retainer pin 29 are assembled by being driven into the inclined groove 20 of the end face member 24 with the washer 19 interposed therebetween. The linear retainer pin 29 has a two-sided width 30 shown in FIG. Next, the fitting of the three members, that is, the thin cylindrical member 22, the shaft 21, and the eight cylindrical coil springs 23, which have been partially assembled in the above state, will be described. First, the cylindrical coil spring 23 is inserted into the thin cylindrical member 22 by about half, and then the shaft 21 is inserted into the other half of the cylindrical coil spring 23. Next, when the three members are assembled while rotating the shaft 21, the three members are assembled in a state of being pressed against each other. Next, the stopper 38 to which the thrust bearing 37 has been previously attached to the rotating member 32 and which has been adhered thereto is fixed to the round nut 30 by the bolt 33. Finally, Case 1
5 and the bearing case 36 are fixed to the electric motor by the tie rods 28. Next, the operation will be described. When the shaft 31 of the electric motor rotates, the rotating member 32 and the thin cylindrical member 22 rotate while being restrained in the axial direction. At this time, the shaft 21 rotates and stops until the stoppers 5 and 6 hit. When the rotation of the shaft 21 stops, the cylindrical coil spring 23 rolls around the outer periphery of the shaft 21. At this time, since the central axis of the cylindrical coil spring 23 is inclined with respect to the axial direction of the thin cylindrical member 22 and the shaft 21, the cylindrical coil spring 23 simultaneously moves in the axial direction. The axial movement of the shaft 21 is connected to the stopper member 11, the guide pin 1, the clamp rod 3, and the clamp claw 2. The operation of the electric guide pin clamp according to the present invention has been described above. The following problems and solutions must be taken into consideration for the rotary linear conversion mechanism used in the present invention. In the rotation linear conversion mechanism, since force is transmitted between the thin cylindrical member 22, the cylindrical coil spring 23, and the shaft 21 by friction, impact braking in the axial direction, inertial force of the rotating body, And excessive rotation torque of the electric motor, etc.
A slip phenomenon occurs between the former three. Due to the accumulation of the slip phenomenon, the relative position of the cylindrical coil spring 23 in the axial direction deviates from the allowable range. In this conversion mechanism, since the shaft 21 moves at twice the speed of the axial direction of the cylindrical coil spring 23, the axial position of the cylindrical coil spring 23 must be absolutely within the allowable range. The axial slip of the coil spring 23 needs to be corrected. This correction must be resolved as follows.
Shaft 21, thin cylindrical member 22, and cylindrical coil spring 2
By changing the pressing force between the three in the axial direction, the cylindrical coil spring 23 slips only in the direction in which the pressing force is reduced when slippage occurs, that is, in only one direction. The stopper member 11 and the stopper 38 are provided so that they are always located within the allowable range. Further, in order to prevent a wedge phenomenon caused by a frictional force between the end face member 24 of the retainer, the stopper member 11 and the stopper 38, thrust bearings 16 and 17 having a low friction coefficient are provided between the both. Next, used for the conversion mechanism,
The retainer of the cylindrical coil spring 23 will be described. The cylindrical coil spring 23 rolls while maintaining a constant inclination angle, and
The centerline of the coil must be spiral.
In this regard, by assembling the linear pin 29 with a constant inclination angle, maintaining the inclination angle of the cylindrical coil spring 23, and providing the flat pin 29 with the two-face width 30, a spiral problem occurs. Solve.

[Example] Guide pin 1 (hard chrome plating after induction hardening) Guide part outer diameter 18 mm. Eccentricity 2mm. Clamp claw 2 (hard chrome plating after induction hardening) Eccentricity 2 mm. Clamp rod 3 Outer diameter 10mm. Shaft 21 (hard chrome plating after induction hardening on the outer peripheral surface) Outer diameter 30 mm. Thin cylindrical member 22 (cold drawn stainless steel tube, honing finish) Inner diameter 50 mm, thin wall thickness 0.8 mm, thick wall thickness 1.5 mm. Cylindrical coil spring 23 (piano wire, outer diameter centerless polished) Wire diameter 2.0 mm, pitch 2.1 mm, coil outer diameter 10.2 mm, coil inner diameter 6.2 mm, free length 39 mm, inclination angle 1 degree. Retainer pin 29 (tool steel, centerless polished) Outer diameter before flattening width 6.0 mm, width across flats 4.5 mm. Electric motor, DC24V, 1.6A, 1500RPM, Rated torque 15N ・ cm. As a result of carrying out under the above conditions, it was confirmed that a clamping force of 500 N was exhibited, the slip at both ends was corrected, and the clamping force was maintained even after the power was turned off.

[Effects of the Invention] An effect of the present invention is to provide a novel mechanism for preventing the attachment of spatter and the like and the invasion of foreign matter during welding in a combination mechanism of a guide pin and a clamp claw. At the same time, electrification can contribute to energy savings.

[Brief description of the drawings]

FIG. 1 is a sectional view of an electric guide pin clamp according to the present invention.

FIG. 2 shows a shape of a sliding surface in the case of a perfect circular guide pin used in FIG.

FIG. 3 shows the shape of a sliding surface in the case of an elliptical guide pin.

FIG. 4 is a sectional view taken along a line AB in FIG. 1;

FIG. 5 is a partially assembled view of a cylindrical coil spring and a retainer of the rotation linear conversion mechanism used in the present invention.

[Explanation of symbols]

 (1) is a guide pin. (2) is a clamp claw. (3) is a clamp rod. (4) is a detent pin. (5) and (6) are stoppers. (7) and (8) are sliding surfaces. (9) is an eccentric hole. (10) is a guide groove. (11) is a stopper member. (12) is a thrust bearing. (13) is a set screw. (14) is a cap. (15) is a case. (31) is an electric motor shaft.

Claims (1)

[Claims] A clamp rod (3) is fixed to a clamp claw (2) having the same end surface shape as the outer peripheral shape of a guide pin (1), and a detent (4) slidable in the axial direction on the guide pin. ), Stoppers (5) and (6) are provided between the guide pin and the clamp rod to enable a finite rotation (for example, 90 degrees and 180 degrees), and one end face (7) of the guide pin and the stopper are provided. An electric guide pin clamp provided with a rotation linear conversion mechanism, wherein the relative axial position of the clamp claw is restricted at a position where the end face (8) of the clamp pawl becomes a sliding surface.