JPS6348328Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a face driver.

[Conventional technology]

When machining a well-known shaft work, the face driver holds both ends of the work between the tail stock and the face driver attached to the main shaft, allowing the work to rotate freely on its axis. The provided teeth bit into the end surface of the workpiece, thereby transmitting the rotational driving force of the main shaft to the workpiece. In the conventional face driver 1, as shown in FIG. 1, a center 3 is fitted into a body 2 so as to be slidable in the axial direction, and the center 3 is pressed toward the workpiece by a coil spring 4 to prevent eccentricity of the body 2. A pair of driving pins 5 are fixed at the position,
The tip of the driving pin 5 is provided with a tooth portion 5a for biting into the end surface of the workpiece.

[The problem that the idea aims to solve]

Since the center 3 of this face driver 1 is slidable in the axial direction, the center 3
The axial center of the main shaft fluctuates relative to the axial center of the main shaft. Therefore, when mounting the workpiece, the center 3 fitted into the center hole at the center of the end face of the workpiece is tilted with respect to the axis of the spindle, that is, the workpiece is mounted with the center 3 fitted in the center hole at the center of the end face of the workpiece tilted with respect to the axis of the spindle. The tooth portion 5a provided at the tip of the driving pin 5 bites into the end surface of the
In this state, processing such as machining and grinding is performed based on the rotational drive of the main shaft. Therefore, it has been difficult to process the workpiece with high accuracy. In addition, even if the center of the workpiece is accurately aligned when the workpiece is mounted, during machining the center may be adjusted based on the vibration force generated on the workpiece due to the rotation of the spindle or the pressing force exerted by the tool on the workpiece. There is a tendency for misalignment of the workpiece to occur as a result of fluctuations in the workpiece, and it is difficult to say that such misalignment of the workpiece can be completely prevented by the pressing force of the driving pin 5 that bites into the end surface of the workpiece. Therefore, the above-mentioned conventional technology has a disadvantage in that it is difficult to achieve high accuracy in machining such as turning and grinding long objects as a result of adopting a structure in which the center is slidable in the axial direction.

Furthermore, in the prior art, the plastic disk 6 and the axial position of the driving pin 5 are adjusted to prevent excessive pressing force from acting on the driving pin 5 based on the axial force applied between the main shaft and the tail stock. Manufacturing, assembly, and maintenance of the face driver 1, such as having a structure that can be held easily, and improving the processing accuracy of each part in order to maintain the mounting accuracy of the center 3 and each driving pin 5. However, it had drawbacks that required time and money.

Furthermore, in the conventional technology, the driving pin 5
is attached to the face driver 1 at a fixed position, so the tooth portion 5a at the tip of each driving pin 5 should be set to be located within a plane perpendicular to the axis of the face driver 1. First, if the axial mounting position accuracy of the pair of teeth 5a is poor, the workpiece cannot be held evenly by both driving pins 5, and the axial force applied between the main shaft and the tail stock is It is not possible to exert the expected clamping force based on the expected gripping force. Therefore, the workpiece oscillates around the part supported by the driving pin 5 with the stronger clamping force, and the center hole that should be supported by the center 3 and the part that should be supported by the other driving pin 5. The workpiece tends to move and vibrate, and the workpiece does not rotate at a sufficient constant speed.
Machining accuracy was poor, and this was also a cause of wavy formation on the machined surface. Therefore, it is necessary to improve the axial mounting position accuracy of both driving pins 5. Even if both driving pins 5 are installed with sufficient precision, if the end face of the workpiece is not machined on a plane perpendicular to the axis of the workpiece with high precision, or if the parting process is not completed completely on the end face of the workpiece. If not, it is impossible to equalize the clamping force on the workpiece by both driving pins 5.

The present invention was developed in view of the above circumstances, and its purpose is to improve machining accuracy and simplify the structure in order to transmit the rotational driving force of the main spindle while holding the end face of a long workpiece. The purpose of the present invention is to provide a face screwdriver with excellent design.

[Means to solve the problem]

In order to achieve the above object, the face driver of the present invention has a center which is coaxial with the main shaft and is detachably attached to the main shaft and is held by a fixed body, and a through screw hole at the front end. A cylindrical body is provided with a screw hole orthogonal to the through screw hole and can move forward and backward in a direction parallel to the spindle axis, a screw portion that engages with the through screw hole is provided on the outer diameter portion, and the through hole is arranged so that the center tip protrudes. In order to prevent relative positional deviation between the adjustment member and the cylindrical body, which are provided with tooth portions in the center and on the workpiece side that engage with the workpiece, and grooves are formed in the outer diameter screw portion parallel to the axis. a screw member that is screwed into a screw hole of the cylindrical body to engage with a groove of the adjustment member; and a biasing means that presses the adjustment member toward the workpiece relative to the fixed body. It became a face driver.

[Effect]

In order to adjust the pressing force of the biasing means by taking into consideration the load force applied to the workpiece, the axial position of the adjustment member relative to the cylinder body is adjusted, and the adjustment member is fixed to the cylinder body with a screw member. do. After that, when the center is engaged with one end of the workpiece and the tail stock is advanced toward the main shaft, the teeth of the adjustment member bite into the workpiece and fix the workpiece, and the workpiece is processed in this state.

〔Example〕

Embodiments of the present invention will be described below with reference to FIG. 2 and the following drawings. 2 is a longitudinal sectional view of a face driver 41 according to an embodiment of the present invention, FIG. 3 is a front view taken in the direction of the arrows in FIG. 2, and FIG. 4 is a side view taken in the direction of the arrows in FIG. The part indicated by the reference numeral 22 in the figure is a flanged body or adapter attached to the end of the main shaft to which the face driver 41 is attached. A center 25 having a taper shank is tightly fitted into a tapered hole 24 provided at the tip 23 of the protrusion of the body 22 . Therefore, the center 25 is connected to the body 2 when parts need to be replaced.
3, and can be attached to the body 23. However, when machining is carried out while holding a workpiece with the face driver 21, the center 25 is moved in a direction perpendicular to the main axis as well as in the axial direction. It doesn't move either. That is, the center 25 is detachably attached to the main shaft and held at a fixed position.

From FIG. 2 to FIG. 4, 42 is the cylinder 4.
3 and a tooth holder 44 as an adjusting member which is adjustable in the axial direction with respect to the cylinder 43. In this embodiment, the tooth holder 44 as an adjustment member with respect to the cylindrical body 43 is configured to be freely adjustable in the axial direction. The head 48 of the screw member 48 is screwed into the screw hole 47 which is threaded through the cylinder body 43 in the radial direction.
By engaging one or more grooves 49 provided on the outer periphery of the tooth holder 44, the tooth holder 44 can be adjusted and locked in the axial direction with respect to the cylindrical body 43.

Further, on the outer periphery of the body tip 23, a driving member 42
A cylindrical body 43 is fitted so as to be movable in the axial direction. A key 29 is attached to key grooves 27 and 28 provided in the body tip 23 and the cylindrical body 43, respectively, so that the cylindrical body 43 rotates integrally with the rotational drive of the main shaft. A screw pin 31 is screwed into the screw hole 30 screwed into the cylindrical body 43.
The head 31a of the head 31a has a slot 3 bored in the body tip 23.
Therefore, the cylinder 43 faces into the slot 32.
can be moved in the axial direction with respect to the body 22 only within a dimension range that allows movement of the screw pin 31, and has a structure to prevent the cylinder body 43 from coming off.

In the cylindrical hole 50 of the cylindrical body 43, an elastic body or a disc spring 34 is interposed as an example of biasing means between the end surface of the body tip 23 and the tooth holder 44, which is an adjustment member.

The tooth holder 44 also has a through hole 51 through which the center 25 is inserted with a predetermined gap in the axial and radial directions.
The pointed end 37 is structured to face the outside of the tooth holder 44. The tooth holder 44 has a pair of teeth 52 extending in the radial direction at a position spaced apart from the tip 37 of the center 25 in the radial direction.

Face driver 41 according to an embodiment of the present invention
is related to the above configuration, and its operating procedure and operation will be explained below.

Processing according to the shape and dimensions of the long workpiece W, the diameter of the center hole C of the workpiece W that depends on the dimensions, the rotational moment around the axis, and the type of processing such as turning or grinding. The disc spring 34 in the usage state determined based on the load force applied to the workpiece W inside and the spring constant of the disc spring 34.
In order to adjust the pressing force, the axial position of the tooth holder 44 with respect to the cylinder body 43 is adjusted.

A workpiece W with a center hole C machined on both end surfaces E of the workpiece W is carried into a machine tool, one center hole is supported by a tail stock (not shown) which can take a known type, and the other center hole C is provided on the main shaft. It is engaged with the tip 37 of the center 25 of the face driver 41 according to the present invention.

Next, the tail stock is moved forward toward the main shaft, so that the tip 37 of the center 25 is completely fitted into the center hole C of the work W, and the teeth 52 of the drive member 42 are bitten into the end surface E of the work W. Processing such as , turning or grinding can be performed. In this way, in this embodiment, the main axis of the workpiece can be held accurately and the workpiece can be held evenly and reliably despite the irregularities of the end face of the workpiece. The pressing force of 34 can be adjusted by means of a screw structure.

Therefore, it goes without saying that adjustment using such a screw structure can be performed manually, and in addition to providing the main shaft with an indexing function that can be of a known type, a rotary drive means for the screw member 48 and a rotational drive means for the screw member 48 are provided. By providing means for indexing the tooth holder 44 in the unlocked state,
It is possible to automate the axial position adjustment of the tooth carrier 44 relative to the barrel 43.

[Effect of idea]

As is clear from the above description, the present invention securely holds the center on the main shaft and elastically supports the adjusting member having teeth by means of a biasing means, so that turning, grinding, and other machining can be performed with high precision. It can be done. In addition, it is possible to deal with irregularities on the end surface of the workpiece, and the position of the adjustment member can be adjusted according to the load force during machining to change the pressing force of the adjustment member, so the workpiece cannot be pushed with excessive force. There is no possibility of slipping between the teeth of the adjusting member and the workpiece due to insufficient pressing force. Moreover, since the structure is simplified, assembly and maintenance become easier, which is a practical advantage.

Furthermore, a groove is formed in the adjustment member, and if a screw member is inserted into this groove and the adjustment member is fixed, the teeth of the adjustment member will bite into the workpiece even when the workpiece is rotated and the workpiece is being processed. Therefore, no rotational deviation occurs relative to the cylindrical body. Therefore, the pressing force of the center does not change during workpiece processing. Furthermore, the tooth portion of the adjusting member does not come off the cylindrical body due to rotational deviation, making it extremely safe to handle.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view showing the prior art, Fig. 2 is a longitudinal cross-sectional view of an embodiment of the present invention, Fig. 3 is a side view taken in the direction of the arrow in Fig. 2, and Fig. 4 is a view taken in the direction of the arrow in Fig. 2. It is a front view. In the figure, 41...face driver, 2
...Body, 25...Center, 29...Key,
34... Disc spring (biasing means), 42... Drive member,
43...Cylinder body, 44...Tooth holder (adjustment member),
48...Screw member, 52...Tooth portion.

Claims (1)

[Scope of claim for utility model registration] A center that is coaxial with the main shaft and is detachably attached to the main shaft and held by a fixed body, and a threaded hole that has a through screw hole at the front end and is perpendicular to the through screw hole. a cylindrical body that can move forward and backward in a direction parallel to the spindle axis, and a threaded part that is threadedly engaged with the through-screw hole on the outer diameter part;
an adjustment member having a through hole in the center of the shaft for protruding the center tip, a tooth portion that engages with the workpiece on the workpiece side, and a groove formed in the outer diameter thread parallel to the axis; and the cylinder. In order to prevent relative displacement with the body, a screw member that is screwed into a screw hole of the cylindrical body to engage with a groove of the adjustment member, and a relative position of the adjustment member with the fixed body. A face driver consisting of a biasing means that presses toward the workpiece.