JPH0453641B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention provides a fitting surface on which a bearing is fitted on the inner periphery, such as a lower cylinder of a video tape recorder.
The present invention relates to a device that performs lead surface processing on a workpiece having a lead surface or a cylindrical surface on its outer periphery.

[Conventional technology]

The lower cylinder used in the video tape recorder has the shape shown in FIG. , and a bearing fitting surface d. FIG. 6 shows the assembled state of the lower cylinder 1, in which a bearing 2 is fitted to the bearing fitting surface d on the inner surface of the lower cylinder 1, and the bearing 2 is connected to the rotating shaft 3.
is held rotatably, and an upper cylinder (not shown) is attached to the rotating shaft 3. Here, rotation axis 3
The coaxiality of the lead surface a and the cylindrical surface b and the perpendicularity of the mounting end surface c are important, and high precision is required.

Conventionally, as a lead surface machining device for such a lower cylinder, a cam-type lathe (for example, a
4341, JP-A-58-4342, JP-A-58-22601, etc.), NC lathe with cam, or NC lathe (e.g., JP-A-60-123201, JP-A-60-90601, etc.) These lathes process the lead surface a, the cylindrical surface b, the mounting end surface c, and the bearing fitting while holding the cylindrical surface e of the lower cylinder (hereinafter referred to as the work) 1 on the main shaft of the lathe. Surface d is processed to obtain the coaxiality of the lead surface and cylindrical surface and the perpendicularity of the mounting end surface with respect to the bearing fitting surface.

[Problem to be solved by the invention]

However, in such a processing method, the sixth
As shown in the figure, after the rotating shaft 3 is assembled on the workpiece 1, there is a problem in that it is difficult to sufficiently improve the accuracy of the coaxiality of the lead surface and cylindrical surface and the perpendicularity of the mounting end surface with respect to the rotating shaft 3. It was hot.

The inventor of the present invention investigated the causes of such accuracy deterioration and found the following matter. That is, when the workpiece 1 is machined as an individual part as described above and assembled as shown in FIG. 6, the accuracy of the bearing 2, the assembly accuracy of the bearing 2 and rotating shaft 3, and the assembly accuracy of the bearing and workpiece 1 are The accuracy of the coaxiality of the lead surface and the cylindrical surface and the perpendicularity of the mounting end surface with respect to the rotating shaft 3 deteriorates, making it difficult to obtain the desired high accuracy.

The present invention has been made based on this knowledge, and an object of the present invention is to provide a lead surface processing device that can eliminate the aforementioned deterioration in accuracy.

[Means to solve the problem]

In order to achieve the above object, in the lead surface machining device of the present invention, the main spindle rotatably held by the headstock has a hollow structure, and the spindle is passed through the main spindle and rotatably held by the main spindle. A first work holding means is provided at the tip of the spindle, and includes a pedestal and a clamp lever for holding one end of the rotating shaft rotatably holding the work and fixing the rotating shaft on the axis of the main spindle, and , a second work holding means including a pedestal for holding the other end of the rotating shaft and a clamp lever is disposed in front of the supporting shaft. A bracket is fixedly provided on the headstock, and one end of the bracket fixedly holds the rear end of the spindle, and the second workpiece holding means is fixed to the other end. Further, a work rotation means is provided at the tip of the main spindle to transmit the rotation of the main spindle to the work.

[Effect]

Before processing the lead surface using the above lead surface processing device, first process the bearing mating surface on the workpiece.
A bearing is attached to this bearing fitting surface to hold the rotating shaft, and the assembled workpiece and rotating shaft are set in a lead surface processing device and processed. That is,
A rotary shaft holding a workpiece rotatably is held by a first workpiece holding means at the tip of the spindle of the lead surface machining device and a second workpiece holding means in front of the first workpiece holding means, and the workpiece is held by the main shaft around the rotary shaft. The lead surface of the workpiece is turned while rotating around the center. Therefore, the influence of the accuracy of the bearing, the assembly accuracy of the bearing and the rotating shaft, the assembly accuracy of the bearing and the workpiece, etc. is eliminated, and it becomes possible to perform highly accurate lead surface machining on the rotating shaft.

Here, the rotating shaft that holds the workpiece is fixedly held by the pedestal and clamp lever that constitute the first and second workpiece holding means, so that it is securely fixed and fixed at a predetermined position with high precision. ,for example,
Compared to a structure in which a fitting hole is provided at the tip of the spindle and the rotating shaft is inserted and fixed into the hole, the positioning accuracy of the rotating shaft is higher, and there is no problem such as rattling during machining, and the high precision of the lead surface is achieved. Processing becomes possible.

In addition, since the second workpiece holding means is attached to the bracket fixed to the headstock, both the first and second workpiece holding means are held on the headstock, and the rotating shaft holding the workpiece can be It is possible to position the lead surface more accurately on the axis of the spindle, and the machining accuracy of the lead surface is further improved. Also,
Since the workpiece is displaced together with the headstock in response to thermal displacement of the headstock, the influence of heat on machining accuracy can be canceled.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

FIG. 2 is a side view schematically showing the entire lead surface processing apparatus according to an embodiment of the present invention, and FIG. 1 is a sectional view of the main parts thereof. In FIG. 2, 11 is a bed, 12 is a headstock attached to the bed 11, and 13 is a main shaft. As can be clearly seen from FIG. 1, the main shaft 13 has a hollow structure and is rotatably held on the headstock 12 via a bearing 14. A pulley 15 is attached to the outer periphery of this main shaft 13, and is connected to a drive motor 17 via a belt 16, as shown in FIG.

In FIG. 1, a hollow support shaft 20 extends through the main shaft 13 and is rotatably provided via a bearing 21. As shown in FIG. The rear end of this support shaft 20 is fixed to a bracket 22 with a bolt 23, and the bracket 22 is fixed to the headstock 12 with a bolt 24.

Therefore, the support shaft 20 is prevented from rotating by this bracket 22. At the tip of the support shaft 20, there is a pedestal 2.
6 and a clamp lever 27 are provided. This pedestal 26 is the third
As shown in the figure, it has a V-shaped groove that receives the rotating shaft 3 of the workpiece 1, and by pressing the rotating shaft 3 into this groove with the clamp lever 27, the rotating shaft 3 is fixed on the central axis of the main shaft 13. The structure is such that it is possible to do so. The clamp lever 27 is rotatably held on a pin 28 and has a pull rod 29 connected to one end thereof. A cylinder 30 and a piston 31 are installed outside the bracket 22 at the rear end of the support shaft 20.
The above-mentioned pull rod 29 is connected to the rod 31A of the piston 31 by a pin 32. Thus, as the piston 31 moves, the clamp lever 27 pivots around the pin 28 to hold or release the rotating shaft 3. These pull rod 29, cylinder 30, piston 31, etc. constitute means for opening and closing the clamp lever 27.

The bracket 22 extends to a position opposite to the tip of the main shaft 13, and a second work holding means 35 having a similar structure is provided at the end thereof opposite the work holding means 25. That is, the workpiece holding means 35 has a clamp lever 37 that is pivotable about a pedestal 36 and a pin 38, and the clamp lever 37 is connected to a rod 41A of a piston 41 sliding within a cylinder 40 via a pull rod 39. has been done. These pull rod 39, cylinder 40, piston 41, etc. constitute means for opening and closing the clamp lever 37.

A pneumatic circuit 44 is connected to the cylinders 30, 40 on both sides. This pneumatic circuit 44 is connected to a pneumatic source 45
Solenoid valve 46 leading to speed control valve 4
7. Equipped with a silencer 48 and the like. In the embodiment, a case has been shown in which the cylinders 30 and 40 are operated by supplying pneumatic pressure, but a hydraulic circuit may be used instead of this pneumatic circuit. In that case, a silencer is not required and a hydraulic tank is provided in its place.

A driving drum 49 is fixed to the tip of the main shaft 13, and a notch 49A is provided at the tip. A driving pin 50 provided on the workpiece 1 is engaged with this notch 49A, and serves to transmit the rotation of the main shaft 13 to the workpiece 1. Therefore, the drive drum 49 and the drive pin 50 constitute a work rotation means for transmitting the rotation of the main shaft to the work.
Furthermore, a cam 51 is attached to the tip of the main shaft 13. This cam 51 has a cam surface 51A corresponding to the lead surface to be machined.

In FIG. 2, 53 is a Z-axis slide;
It is provided so as to be movable relative to the bed 11 in a direction parallel to the main shaft axis. An X-axis slide 54 is held on this Z-axis slide 53 so as to be movable in a direction perpendicular to the spindle axis, and a tool rest (not shown) is placed on this X-axis slide 54. A tool is attached to perform the turning described below. Furthermore, the Z-axis slide 53 and the X-axis slide 5
4 is connected to means (not shown) for moving the work 1 so as to perform predetermined turning on the work 1. Any known tools that can perform lead surface machining, cylindrical surface machining, etc. on a workpiece can be used as the tool, the tool post, the X-axis slide, the Z-axis slide, and their drive mechanism, so their explanation will be omitted. . Further, as shown in FIG. 1, the X-axis slide 54 has a reference member 55 for setting the workpiece mounting position.
is provided to move in the vertical direction. When this reference member 55 is raised with the X-axis slide 54 positioned at the reference position, its left surface becomes a reference surface for setting the mounting position of the workpiece 1 in the main axis direction. By pressing the workpiece 1 against 55, the workpiece is positioned at a predetermined position.

Next, a processing operation by the lead surface processing apparatus having the above structure will be explained. First, the bearing fitting surface d of the workpiece 1 shown in FIG. 5 is machined using another turning device, and the rotating shaft 3 is held on the workpiece 1 via the bearing 2 as shown in FIG. 6. Further, a drive pin 50 is attached to this work 1. Next, the rotating shaft 3 attached to the workpiece 1 is placed on the pedestals 26 and 36 of the pair of workpiece holding means 25 and 35 shown in FIG.
In addition, the drive pin 50 of the workpiece is connected to the drive drum 49.
The tension rod 2 is engaged with the notch 49A of
The rotating shaft 3 is fixed to the pedestals 26, 36 by operating the clamp levers 27, 37 via the clamp levers 9, 39.
At this time, the X-axis slide 54 is set at the reference position and the reference member 55 is raised.
By pressing the workpiece 1 against the workpiece 5, the position of the workpiece in the spindle axis direction is positioned at a predetermined position. In this way, the rotating shaft 3 and the workpiece 1 are mounted at predetermined positions on the spindle axis. When the main shaft 13 is rotated in this state, the rotation of the main shaft 13 is transmitted to the workpiece 1 through the driving drum 49 and the driving pin 50.
The workpiece 1 rotates around the rotating shaft 3. While the workpiece 1 is rotating, the lead surface a, the cylindrical surface b, and the mounting end surface c are lathed using a tool 57, as shown in FIG. Note that the order of these processes is arbitrary. Through the above operations, a lower cylinder for a video tape recorder is created, which has a lead surface a with highly accurate coaxiality with the rotating shaft 3, a cylindrical surface b, and a mounting end surface c with a highly accurate perpendicularity. Obtainable.

In the above embodiment, the cam 51 for machining the lead surface is provided at the tip of the spindle, but it goes without saying that this cam may be omitted and the machining of the lead surface may be performed by NC controlling the tool.

〔Effect of the invention〕

As explained above, the lead surface machining device of the present invention has a support shaft installed in a hollow main shaft that is rotatably driven so as not to rotate (therefore, rotatable with respect to the main shaft), and the support shaft A first work holding means consisting of a pedestal and a clamp lever for fixedly holding the rotating shaft of the work on the spindle axis is provided at the tip, and a second work holding means having a similar configuration is provided in front of the first work holding means, The system is equipped with a workpiece rotation means that transmits the rotation of the main shaft to the workpiece, so the rotating shaft attached to the workpiece can be accurately rotated by the cradle and clamp lever of the first and second workpiece holding means. It is held fixed on the spindle axis,
In addition, the workpiece can be rotated about the rotation axis by the main shaft, and in this state, the lead surface of the workpiece is machined by the turning means, thereby making it possible to machine the lead surface with high precision. Moreover, when rotating the workpiece, rotational torque is transmitted to the workpiece by the main shaft rotating on the same axis as the rotating shaft that supports the workpiece, which places an extra load on the rotating shaft holding the workpiece in addition to the workpiece's own weight. Therefore, lead surface machining is possible with minimal deflection of the rotating shaft. As a result, lead surface processing can be performed with extremely high precision.

Further, since the rear end of the spindle is held and fixed to one end of the bracket fixed to the headstock, and the second work holding means is fixed to the other end, the first and second workpieces for holding the work are fixed. The holding means is held in its entirety by the headstock, making it possible to position the rotary shaft holding the workpiece on the spindle axis even more accurately, and to avoid thermal effects on machining accuracy due to thermal displacement of the headstock. This makes it possible to further improve the machining accuracy of the lead surface.

As shown in the example, it is possible to perform not only lead surface machining but also cylindrical surface machining and mounting end face machining with the rotating shaft fixedly held by the workpiece holding means. Various types of turning can be performed by one chuck of the rotating shaft, greatly improving work efficiency, and making it possible to achieve highly accurate coaxiality or perpendicularity to each machined surface with respect to the rotating shaft. becomes.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of a lead surface processing device according to an embodiment of the present invention, FIG. 2 is a side view of the lead surface processing device, and FIG. 3 is a work holding means used in the lead surface processing device. 4 is a sectional view of a main part explaining the turning operation in the lead surface machining device, FIG. 5 is a sectional view showing an example of a workpiece, and FIG. 6 is a sectional view showing the usage state of the workpiece. be. 1... Workpiece, 2... Bearing, 3... Rotating shaft, 1
1...bed, 12...headstock, 13...main spindle,
15... Pulley, 16... Belt, 17... Drive motor, 20... Support shaft, 22... Bracket, 2
5, 35... Work holding means, 26, 36... cradle, 27, 37... clamp lever, 28, 38
...Pin, 29,39...Tension rod, 30,40
...Cylinder, 31, 41...Piston, 49...
...Driving drum, 50...Driving pin, 54...
X-axis slide, a...Lead surface, b...Cylindrical surface,
c...Mounting end surface, d...Bearing fitting surface.

Claims (1)

[Claims] 1 A headstock, a hollow main shaft rotatably held by the headstock, a main shaft driving means for rotating the main shaft, a spindle passing through the main spindle and rotatably held by the main spindle, and the support. a first work holding means provided at the tip of the shaft and comprising a pedestal and a clamp lever for holding one end of the rotating shaft of the workpiece and fixing the rotating shaft on the main shaft axis; and means for opening and closing the clamp lever. and a second work holding means, which is located in front of the spindle and includes a pedestal and a clamp lever that holds the other end of the rotating shaft of the workpiece and fixes the rotating shaft on the main shaft axis. a means for opening and closing the clamp lever; a bracket fixed to the headstock for holding and fixing the rear end of the spindle and having the second work holding means fixed to the other end; and a bracket attached to the tip of the spindle. a lead surface provided with a work rotation means for transmitting the rotation of the main shaft to the work; and a turning means for performing lead surface machining on the work held by the first and second work holding means and rotated by the main shaft. Processing equipment.