JPH0418725Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention uses a plurality of cutting tools fixed to a boring bar that is connected to a main shaft, rotates together with the main shaft, and moves in the axial direction. This invention relates to a line boring tool for machining multiple holes located above at once.

(Prior art) Generally, when machining multiple holes located on the same axis at once, a so-called line boring tool such as the one described in Japanese Utility Model Application Publication No. 178508/1983 is used. has been done. This type of line boring tool is generally rotated by a motor etc.
In addition, it is composed of a main shaft that can move forward and backward in the axial direction, a boring bar that is connected at one end to the main shaft and has a plurality of cutting tools arranged in parallel in the axial direction, and a support member that supports the boring bar. .
Then, the boring bar is rotated by the main shaft, and the main shaft is moved in the axial direction to push out the boring bar, thereby cutting a plurality of cutting tools arranged in parallel on the boring bar into a plurality of cutting tools located on the same axis. By bringing it into contact with the holes, a plurality of these holes can be machined at once.

(Problems to be Solved by the Invention) By the way, as described above, the boring bar is rotated by the main shaft and pushed out in the axial direction, and a plurality of cutting tools are arranged in parallel in the axial direction of the boring bar. When machining holes at once, that is, when performing push-cutting, the cutting load acting on a plurality of cutting tools is transmitted to the boring bar via the plurality of cutting tools.
For this reason, the boring bar undergoes buckling deformation, and as a result, the boring bar wobbles around its axis, resulting in a significant decrease in the machining accuracy of the plurality of holes, and also Due to the buckling deformation of the boring bar, a misalignment occurs between the axis of the boring bar and the axis of the main shaft and the member supporting the boring bar, resulting in seizure between the boring and the main shaft and supporting member. will occur.

Therefore, the present invention has developed a line in which multiple holes located on the same axis are machined at once using multiple cutting tools fixed to a boring bar that is connected to the main spindle, rotates together with the main spindle, and moves in the axial direction. An object of the present invention is to provide a line boring tool that can reliably prevent buckling deformation of the boring bar that occurs during machining and seizure that occurs between the boring bar and the main shaft. .

(Means for Solving the Problems) In order to achieve the above object, the present invention is characterized by the following configuration.

That is, a line boring tool for machining multiple holes located on the same axis at once includes a main body attached to a main shaft that rotates and moves in the axial direction, one end of which is loosely fitted to the main body, and the above-mentioned a boring bar in which a plurality of cutting tools for machining a plurality of holes are disposed in the axial direction; and a boring bar that is inserted in a diametrical direction into a loose fitting portion between the main body and the boring bar to connect the main body and the boring bar; A connecting pin that transmits the tensile force from the main shaft to the boring bar through the main body, and a connecting pin that is provided at a loose fitting part between the main body and the boring bar and transmits the rotational force from the main shaft to the boring bar through the main body. A rotational force transmitting member, a support member that supports at least two front and rear ends of the boring bar, and a support member that is inserted into a loosely fitting portion of the boring bar with the main body of the boring bar so that the connecting pin can be moved when the boring bar is pulled. The device is configured to include a ball member that comes into contact with the side surface, and a gap adjustment means that is provided on the main body and presses the ball member against the connection pin to adjust the state of contact with the connection pin.

(Function) According to the above configuration, while the boring bar is rotated and moved by being pulled in the axial direction, a plurality of cutting tools fixed in the axial direction of the boring bar are used to position the boring bar on the same axis. Since a plurality of holes are machined at once, the boring bar does not undergo buckling deformation due to the influence of cutting loads during machining. Therefore, the boring bar is reliably prevented from wobbling around its axis, thereby further improving the machining accuracy of the plurality of holes.

Further, one end of the boring bar is supported in a loosely fitted state, that is, a floating state, with respect to the main body attached to the main shaft, and a ball member inserted into the boring bar by a gap adjustment means, Since it is configured so that the contact state with the connecting pin that contacts the main body, in other words, the floating state between the main body and the boring bar, can be adjusted appropriately by the gap adjustment means, even if it is attached to the main shaft side, that is, the main shaft. Even if there is a misalignment between the axis of the main body and the axis of the boring bar connected at one end to the main body, the boring bar is reliably prevented from seizing on the main shaft. In particular, in the present invention, the floating state adjustment performed by the gap adjustment means is performed using a connecting pin for transmitting tensile force from the main shaft side to the boring bar via the main body. The structure is simpler than when this adjustment and the transmission of the tensile force are performed by separate members, respectively.

(Example) Next, a specific example of the present invention will be described based on the drawings.

Figure 1 shows line boring tool 1 of this embodiment.
This line boring tool 1 includes a main shaft 2 that is rotated by a motor or the like (not shown) and that can move forward and backward in the axial direction (left and right directions in the drawing), and the main shaft 2. A main body 5 is detachably attached to a quill 3 fixed to the tip of the quill 3 via an adjuster nut 4, and one end is connected to the main body 5, and a plurality of cutting tools 6 are connected in the axial direction.
6 and 6'...6' are fixed at predetermined intervals, respectively, and a support member 8 that supports at least two front and rear ends of the boring bar 7.
a, 8b. Thereby, the boring bar 7 is rotated by the main shaft 2, and as the main shaft 2 moves forward and backward in the axial direction, the boring bar 7 is also moved in the axial direction. Then, as shown in FIG. 1, a plurality of holes 9a...9a and 9b...9b located on the same axis previously formed in a workpiece W such as a cylinder head formed by casting etc. Cutting tools 6...6 and 6'...6' fixed at predetermined intervals in the axial direction around the outer periphery of the boring bar 7 are used to perform machining at one time.

In this embodiment, the support members 8a,
8b is fixed on, for example, a frame 11 via the same bracket 10, and the workpiece W is placed and fixed on a table 12 which is vertically movable.

However, in this embodiment, the main body 5 and one end of the boring bar 7 are connected in the following manner. That is, as shown enlarged in Fig. 2,
A boring bar 7 is inserted into the hole 5a formed in the main body 5.
By loosely fitting the base end 7a of the boring bar 7, and inserting the connecting pin 13, which is also diametrically installed in the main body, into the diametrical through hole 7b provided in the base end 7a of the boring bar 7, The base end 7a of the boring bar 7 is connected to the main body 5 so that the tensile force from the main shaft 2 side can be transmitted from the main body 5 to the boring bar 7, and in a floating state, that is, movable by a predetermined amount in the diametrical direction. has been done. In that case, the through hole 7b at the base end 7a of the boring bar 7 is made larger in diameter than the outer diameter of the connecting pin 13, so that the boring bar 7 can also move a certain amount in the axial direction with respect to the main body 5. has been done. Inside the base end 7a of the boring bar 7 is a pressing member 1 whose one end is attached to the inner surface of the base end 7a.
4a, a ball member 15 whose other end can come into contact with a notch surface 13a formed on one side of the connection pin 13;
is inserted therein, and a ball member 16 whose one end abuts against the pressing member 14b is interposed at the rear end of the base end 7a.

On the other hand, the connecting pin 1 is provided at the rear of the main body 5.
3 and the ball member 15, in other words, the floating state between the main body 5 and the base end 7a of the boring bar 7 connected thereto in a floating state. is provided. The gap adjustment means 17 includes a wedge body 18 which has a tapered surface on one side and is movable forward and backward in a direction perpendicular to the axis of the main body 5;
Adjustment screw 19 for moving 8 forward or backward by a predetermined amount
a, 19b, and each of these adjustment screws 19a, 19b
Lock screws 20a, 20 to prevent loosening of
b, one end engages with the tapered surface of the wedge body 18 and moves in the axial direction of the main body 5 as the wedge body 18 advances and retreats, and the other end engages with the tapered surface of the wedge body 18.
6 and a press pin 21 that comes into contact with the pin 6. The ball member 16 of this pressing pin 21
By adjusting the contact pressure on the ball member 15, the contact state between the ball member 15 and the notch surface 13a of the connecting pin 13 changes, thereby controlling the flow of the base end 7a of the boring bar 7 against the main body 5. The status has been adjusted. Note that the tip of the screw member 22 screwed into the main body 5 is engaged with the upper surface of the pressing pin 21, so that the pressing pin 21 is inadvertently rotated and engaged with the wedge body 18. It is designed so that the state does not change.

Further, the notch pin 23 is fitted into the lower end of the connecting pin 13, and the connecting pin 13 is inadvertently rotated, causing the notch surface 1 of the connecting pin 13 to be inadvertently rotated.
3a, and the ball member 1 whose one end is in contact with the ball member 3a.
This is to prevent the state of contact with 5 from changing.

Further, a drive pin 24 is passed through the base end 7a of the boring bar 7 in a direction perpendicular to the axis of the base end 7a, and as shown enlarged in FIG. Both ends 24a, 24a of the pin 24 are connected to a groove 5b formed in the main body 5.
are in contact with the inner circumferential surfaces 5b' and 5b', respectively. As a result, when the main body 5 is rotated together with the main shaft 2 in the direction indicated by arrow A in FIG.
4, the boring bar 7 is also rotated in the same direction. By moving the main shaft 2 in the direction shown by arrow B in FIG. 1 while rotating the main shaft 2, the boring bar 7 is rotated via the main body 5 attached to the main shaft 2.
and a support member 8 that supports the boring bar 7
The plurality of cutting tools 6 are fixed at predetermined intervals in the axial direction of the boring bar 7 by being guided by arrows a and 8b and pulled in the direction shown by the arrows B.
...6 and 6'...6' are configured to machine a plurality of holes 9a...9a and 9b...9b in the workpiece W at once.

In addition, in this embodiment, in one cutting process, the workpiece W is cut by the plurality of cutting tools 6...6.
After machining the plurality of holes 9a...9a at the same time, the plurality of cutting tools 6'...6' simultaneously machine the remaining holes 9b...9b. 6 and 6'...
6' are fixed to the boring bar 7 at predetermined intervals.

Furthermore, the support members 8a and 8b are each constructed as follows. That is, as shown in an enlarged view in FIG.
The bushes 26a, 26b are rotatably supported via the bushes 25b', and the boring bar 7 is held in sliding contact with the bushes 26a, 26b, so that the boring bar 7 can be reliably centered. It is supported between each support member 8a, 8b so as to be able to move in the axial direction in a state in which the support member 8b is held in place. Incidentally, on the inner peripheral surface of the bush 26a in the support member 8a located at least on the main shaft 2 side, cutting tools 6...6 and 6'... are provided in the axial direction.
A groove 27 is formed for passing the tip of each bush 26a, 26b, and a lock nut 28a is provided at one end of each bush 26a, 26b to prevent the bushes 26a, 26b from shifting in the axial direction.
28b are screwed together.

Here, as shown in FIG. 1, to explain the case where the line boring tool 1 of this embodiment is used to set the work W to the state immediately before machining, the work W is first placed on the table 12. After the table 12 is fixed in place, the table 12 is moved to a predetermined position, and as shown in an enlarged view in FIG.
...9b and 9b...The workpiece W is positioned so that the axes of 9b are offset from each other. As a result, a plurality of cutting tools 6...6 fixed to the boring bar 7
The tips of the holes 9a...9b and 9b...9b in the workpiece W do not come into contact with the plurality of holes 9a...9b, 9b...
It becomes possible to pass through 9b. Next, spindle 2
is sent out in the axial direction (rightward in Figure 1),
The tip of the boring bar 7 is connected to the support member 8a and a plurality of holes 9a...9a, 9 in the workpiece W.
b... 9b, and move the boring bar 7 so that the tip body is supported within the support member 8b. At this time, as mentioned above, the groove 27 through which the tips of the plurality of cutting tools 6...6 and 6'...6' can pass is formed on the inner peripheral surface of the bush 26a in the support member 8a. These plurality of cutting tools 6...6, 6'...6' are connected to the bush 26a.
It will pass through the inside of the bush 26a without interfering with the inside of the bush 26a. Thereafter, the table 12 is moved again, and as shown by the chain line in FIG. By aligning the axis of the boring bar 7, the workpiece W can be set in a state immediately before machining, as shown in FIG.

Next, to explain the operation of this embodiment, in this embodiment, the boring bar 7 is rotated via the main body 5 attached to the main shaft 2, and the main shaft 2 is moved in the direction shown by the arrow B in FIG. While moving and pulling the boring bar 7 in the direction of the arrow B, a plurality of cutting tools 6...6 and 6' fixed in the axial direction of the boring bar 7 are
...6' is a plurality of holes 9a in the workpiece W...9
b and 9b...9b, these holes 9a...9a, 9b...9b
Since the boring bar 7 is designed to be machined, the boring bar 7 does not undergo buckling deformation due to the influence of the cutting load during machining, and the boring bar 7 supports the support members 8a, 8a,
8b, the boring bar 7 will not wobble around its axis. This further improves the machining accuracy of the plurality of holes 9a...9b and 9b...9b.

Furthermore, with respect to the main body 5 attached to the main shaft 2,
The base end 7a of the boring bar 7 is supported in a floating state, and the boring bar 7 is supported by a gap adjustment means 17 provided in the main body 5.
a ball member 15 inserted into the base end 7a of the
The state of contact with the connecting pin 13 that contacts this, in other words, the base end 7 of the main body 5 and the boring bar 7
The floating state with the gap adjusting means 1
7, so that even if the main shaft 2 side, that is, the axis of the main body 5 attached to the main shaft 2, and the axis of the boring bar 7 to which the base end 7a is connected, Even if there is a misalignment with the center, the boring bar 7 is reliably prevented from seizing on the spindle 2 during cutting.

(Effect of the invention) As described above, the present invention rotates the boring bar by the main shaft and moves it in the axial direction, and uses a plurality of cutting tools fixed in the axial direction of the boring bar to position the boring bar on the same axis. In a line boring tool that is designed to machine multiple holes at once, the boring bar and the main shaft are connected in a floating state via a main body attached to the main shaft, and the floating state is moderately controlled. By providing a gap adjustment means for adjusting the gap and moving the boring bar in the axial direction, the plurality of holes are machined at once, so that the boring bar does not buckle during machining as in the conventional method. Never deformed. As a result, the boring bar is reliably prevented from wobbling, which further improves the machining accuracy of multiple holes, and also reliably prevents seizure between the boring bar and the main shaft. become. and,
In particular, according to the present invention, the above-mentioned adjustment of the floating state is performed using a connecting pin that transmits the tensile force from the spindle side to the boring bar, so that the connecting part of the boring bar is simply configured. It turns out.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a front view showing a line boring tool according to the embodiment, and FIG. 2 is a longitudinal cross-sectional view showing the main parts of the embodiment.
FIG. 3 is an enlarged sectional view taken along the line 1--FIG. FIG. 5 is an enlarged cross-sectional view of a main part for explaining the setting state immediately before machining of a workpiece. 1... Line boring tool, 2... Spindle,
5... Body, 6, 6'... Hole, 7... Boring bar, 7a... Base end, 8a, 8b... Support member, 9a, 9b... Cutting tool, 13... Connection pin, 15... ... Ball member, 17 ... Gap adjustment means, 24 ... Rotational force transmission member (drive pin).

Claims (1)

[Scope of utility model registration request] A line boring tool for machining multiple holes located on the same axis at once, which includes a main body attached to a main shaft that rotates and moves in the axial direction, one end of which is loosely fitted to the main body, and the above-mentioned a boring bar in which a plurality of cutting tools for machining a plurality of holes are disposed in the axial direction; and a boring bar that is inserted in a diametrical direction into a loose fitting portion between the main body and the boring bar to connect the main body and the boring bar; A connecting pin that transmits the tensile force from the main shaft to the boring bar through the main body, and a connecting pin that is provided at a loose fitting part between the main body and the boring bar and transmits the rotational force from the main shaft to the boring bar through the main body. A rotational force transmitting member, a support member that supports at least two front and rear ends of the boring bar, and a support member that is inserted into a loosely fitting portion of the boring bar with the main body of the boring bar so that the connecting pin can be moved when the boring bar is pulled. It is characterized by comprising: a ball member that comes into contact with the side surface; and a gap adjustment means that is provided on the main body and presses the ball member against the connection pin to adjust the state of contact with the connection pin. Line boring tool.