JPH0651254B2 - Reciprocating tool holding device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Applicability> The present invention relates to a reciprocating tool holding device for reciprocating a chuck (tool holding member) holding a cemented carbide tool at high speed.

<Prior Art> In many cases, a conventional holding device of this type converts the rotational movement of a prime mover such as an electric motor or an air motor into a reciprocating movement of a chuck, which is a tool holding member, and transmits it. The stroke of the reciprocating motion of this chuck was always constant, and it could not be used for multiple purposes with a single one.

<Problems to be Solved by the Invention> The present invention adjusts the stroke of the reciprocating motion by one reciprocating tool holding device, and can be used, for example, for cutting and engraving relatively small strokes or for jewelery. (EN) Provided is a reciprocating tool holding device which can be used for removing sludge by large grinding or welding.

Further, since the present invention is a tool holding device, an abnormal load is applied to the tool and its tool holding member during machining for some reason, but in order to avoid damage to the tool due to this load, the tool holding member is It is an object of the present invention to provide a reciprocating tool holding device that applies a cushioning means.

<Means for Solving Problems> To this end, the gist of the present invention is to provide a first force transmission means that is integrated with an output shaft of a prime mover and that includes a shaft portion and a swash plate portion on the front side. A movement changing portion arranged to come into contact with the swash plate portion at an arbitrarily selectable radial position, and a movement changing portion for changing the rotational movement of the first force transmitting means by the prime mover into a reciprocating movement; Second force transmitting means for contacting the changing portion and transmitting the reciprocating motion to the tool holding member,
In the reciprocating tool holding device, the second force transmitting means moves forward and backward based on the reciprocating motion of the motion changing portion. Another aspect of the present invention is a reciprocating tool holding device in which a cushioning member for absorbing a certain amount of overload on the tool holding member is interposed between the tool holding member and the second force transmitting means.

<Example> Next, a preferred embodiment of the handpiece type reciprocating motion tool holding device of the present invention shown in the accompanying drawings will be described.

In FIGS. 1 and 3, a cutting bit (not shown) made of cemented carbide is inserted into a chuck 2 as a tool holding member, and a chuck holding screw is screwed into a screw hole of a front sheath 3 of a tool holding device body 1. Held by 4. The mechanism for reciprocating the cutting bit will be described. The tip of the output shaft 5 of a motor (which may be an electric motor or an air motor) (not shown) is formed into a square shape and is housed in a corresponding square hole of the connecting joint 6. , Rotates integrally with the first force transmission means (comprising the shaft portion 7 and the swash plate portion 8) housed on the other side of the connecting joint 6. 9 is a joint 6 and a shaft portion 7.
It is a pin for rotating and. A swash plate portion 8 is integrally formed at the left end of the shaft portion 7. 10
Is a notch for preventing an imbalance in weight of the swash plate portion 8 when the first force transmitting means rotates. The shaft portion 7 is housed in the rear sheath 11 of the tool holding device body 1 and held by a needle bearing 12 and a thrust bearing 13.

On the other hand, the swash plate 8 has a push rod 14 that abuts on one side.
However, in order to change the reciprocating motion stroke, the outer teeth 2
It is housed in the through hole 16 of the position fixing member 15 provided with 1. The through hole 16 is formed at a position eccentric to the central axis of the position fixing member 15. Position fixing member 15
A groove 17 is formed on the lower outer circumference at an angle of about 180 °, and a screw 18 screwed to the outer surface of the rear sheath 11 is fitted in the groove 17. On the outer surface of the rear sheath 11, a ring member 19 having inner teeth 20 formed in a protruding manner is fitted, and since the inner teeth 20 and the outer teeth 21 of the position fixing member 15 mesh with each other, the ring member 19 is formed. When the position fixing member 15 is manually rotated, the position fixing member 15 is accordingly rotated within the range of the groove 17, that is, over an angle of about 180 °, and
By engaging the screw 18 and the groove 17, the position fixing member 15
However, as described above, it is rotatably but fixedly held. Spring receiving piece 2 with T-shaped cross section
2 is positioned such that the outer surface of the T-shaped base portion contacts the other side of the push rod 14 of the position fixing member 15, and the threaded portion formed on the T-shaped protrusion of the second force transmission means 23. It is integrated with the second force transmission member 23 by being screwed into the corresponding screw hole. The second force transmission means 23 is fitted in the inner hole of the front sheath 3. The push rod 14 has a shape in which balls are provided at both ends of the shaft portion, and one side of these balls is in contact with the slope portion 8 and the other side is in contact with the flat surface of the base portion of the spring receiving piece 22, respectively. Through holes 24 are formed at two locations on the upper side of the second force transmission means 23. Spring cases 25 serving as spring retainers are housed in these through holes, and the blind plate of the case 25 is accommodated. Is in contact with the inner hole surface of the sheath 3. A spring 26 is housed in the outer spring case 25, and protrudes from the open surface of the spring case 25 on the right side of the case 25 in the figure and abuts on the spring receiving piece 22. By applying the springs 26 to the two locations on both sides of the location where the force of the push rod 14 is received, distortion of the spring receiving piece 22 and the second force transmitting means 23 integrated with this is prevented. The protruding length of the spring 26 from the open surface of the spring case 25 is set to a value larger than the distance a between the upper and lower ends of the swash plate portion 8. When the vibration of the entire holding device matches the natural frequency of the spring 26, surging occurs. Therefore, even if the pitch or strength of the two springs 26 is changed and the vibration of one spring 26 matches the vibration of the holding device. The vibration of the other spring 26 should not match the vibration of the retaining device. In the figure, 27 is a ball cage fitted on the outer surface of the second force transmission means 23, and the multiple recesses on the surface thereof have the second force transmission means 23 inside the front sheath 3. A large number of balls 29, which are stroke bearings 28 for smoothly reciprocating, are fitted. An annular chuck stopper 30 having an L-shaped cross section is provided at the left end of the second force transmitting means 23.
3, and the chuck stopper 30 is in contact with the end surface of the second force transmission means 23 and the shoulder portion 32 of the enlarged portion 31 of the chuck 2. The chuck stopper 30, the chuck 2, and the second force transmitting means 23 are adapted to reciprocate within the range of the clearance 33 formed in the front sheath 3 as described below. The chuck pressing screw 4 projects into an annular groove 34 formed on the outer surface of the chuck 2.
The lengths of the clearance 33 and the annular groove 34 are set to values larger than the distance a. Reference numeral 35 is a buffer member of the tool holding member which is directly overloaded from the tool interposed between the rear end surface of the chuck 2 and the rear end surface of the inner hole of the cylindrical portion 36 in front of the force transmission means 23, that is, compression. It is a coil spring.

Next, the operation of the reciprocating tool holding device described above will be described.

When a motor (not shown) such as an electric motor or an air motor is rotated, the square tip of the output shaft is fitted into the corresponding square hole of the connecting joint, so that the connecting joint 6
The shaft portion 7 is rotationally driven via. When the shaft portion 7 rotates, the push rod 14, which is pressed against the swash plate portion 8 integrated with the shaft portion 7 by the spring 26, reciprocates in the left-right direction in the drawing while receiving the action of the spring 26. The stroke of this reciprocating motion is determined by the radial position at which the push rod 14 is in contact with the swash plate portion 8. The link member 19 is used to adjust the radial position to a desired value. That is, when the ring member 19 is manually rotated within an angle range of 180 ° defined by the range of the groove 17, the position fixing member 15 in which the inner teeth and the outer teeth are meshed is also rotated accordingly. However, the push rod 14 changes its radial position as indicated by a double arrow A in the sectional view of FIG. The radial position of the push rod 14 shown by the solid line in FIG. 2 corresponds to the maximum stroke position of the cutting tool, and the radial position thereof shown by the one-dot chain line corresponds to the minimum stroke position of the cutting tool. There is. When the minimum stroke position of the cutting tool coincides with the horizontal center axis line BB of the shaft portion 7, a zero stroke state occurs, so in any case, the minimum stroke position is the horizontal center axis line BB of the shaft portion 7. As above
It is necessary to determine the radial position of the through hole 16. The push rod 14 is constantly in pressure contact with the swash plate portion 8 by the two springs 26 housed in the spring case 25 during its reciprocating motion. When the push rod 14 reciprocates, the spring receiving piece 22 and the force transmitting means 23 integrated with the spring receiving piece 22 also reciprocate, and the front cylindrical portion 36 of the force transmitting means 23 is moved.
Is then smoothly guided by the stroke bearings 28 into the inner bore of the front sheath 3. The shoulder portion 32 of the rear widened portion 31 of the chuck 2 and the end face of the cylindrical portion 36 are held by the radial portion of the chuck stopper 30, and the chuck stopper 30 and the cylindrical portion 36 are fixed to each other by screwing. Thus, the chuck 2 reciprocates as the cylindrical portion 36 reciprocates. The shock generated during the forward movement of the tool is damped by the coil spring 35 between the second force transmission means 23 and the chuck 2. The chuck stopper 30 reciprocates within the clearance 33, and the chuck 2 reciprocates within the groove 34 on the chuck side surface.
Since the length of the groove 34 and the clearance 33 is set to a value larger than the distance a, it is possible to avoid the movable portion from hitting the fixed portion during the reciprocating motion. Also, the length by which the spring 26 projects from the open surface of the spring case 25 is
Since the value is set to be larger than the distance a, it is also possible to prevent the spring pressing piece 22 from hitting the spring case 25.

<Effects of the Invention> As described above, according to the reciprocating motion tool holding device of the present invention, the swash plate portion and the movement changing portion of the first force transmission means cause the rotational movement of the motor to move to the tool holding member. The stroke of the reciprocating motion can be adjusted because the motion changing part is in contact with and moving in the radial direction of the swash plate part.

Further, the reciprocating tool holding device according to the present invention is used for adjusting the stroke of the reciprocating motion, for example, for engraving of small strokes and polishing of jewels, and further, for removing sludge by grinding or welding of a portion having a large stroke and difficult to approach. Also used for removal.

Further, according to the present invention, even when the tool holding member is overloaded, the tool holding member is loosened by the buffer member between the second force transmitting means and damage to the tool can be avoided.

[Brief description of drawings]

1 is a central longitudinal sectional view showing a reciprocating motion tool holding device according to the present invention, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG.
FIG. 1 is an exploded perspective view of a reciprocating tool holding device according to the present invention. Explanation of reference numerals 2 ... Chuck (tool holding member), 5 ... Output shaft of prime mover, 7 ... Shaft part, 8 ... Swash plate part, 14 ... Push rod (motion change part), 15 ... Fixed position Member (movement changing portion), 23 ... Second force transmitting member, 35 ... Coil spring.

Claims (3)

[Claims] 1. A first force transmitting means integrated with an output shaft of a prime mover, comprising a shaft portion and a swash plate portion on the front side, and a reciprocating movement of the first force transmitting means by the prime mover. And a second force transmission means for moving the tool holding member forward and backward based on the reciprocating motion of the motion changing unit, and adjusting the stroke of the reciprocating motion of the motion changing unit. In order to achieve this, the reciprocating motion tool holding device is characterized in that the motion changing portion is provided so as to be able to contact and move in the radial direction of the swash plate portion. 2. The motion changing portion comprises a push rod that comes into contact with the swash plate portion and the second force transmitting means, and a position fixing member having an eccentric through hole for accommodating the push rod. A reciprocating tool holding device according to claim 1. 3. The reciprocating tool holding device according to claim 1, further comprising a buffer member interposed between the tool holding member and the second force transmitting means for absorbing a certain amount of overload on the tool holding member.