JPS6218333Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field This invention relates to a machine tool such as a drilling machine having a step feed function.

Prior Art A machine tool having this type of step feed function is described in, for example, Japanese Utility Model Publication No. 18997/1983. In this conventional machine tool shown in Fig. 10, when the start button is operated,
When the control rod 102 supporting the drill 101 advances rapidly and the slide dog 103 on the control rod 102 engages the valve protrusion 104, the control rod 102 is switched to slow feed. In this state, the slide dog 103 contacts the bearing portion 105 of the case and is prevented from moving forward, but the control rod 102 continues moving forward. In other words, the slide dog 103 is the control rod 1.
02 and is relatively moved backwards.

Then, when a predetermined time elapses, the control rod 102 shifts to rapid retraction, and when the dog 106 acts on the limit switch 107, the control lever 102 shifts to rapid forward movement again, and when the slide dog 103 engages with the valve protrusion 104. The control rod 102 is again switched to slow feed.
In this case, since the slide dog 103 has been moved more rearward than the previous time, the switching to slow feed is performed at a more advanced position.

When this operation is repeated and the drilling by the drill 101 reaches a predetermined depth, the dog 108 acts on the limit switch 109 to switch the control rod 102 to rapid retraction, and the solenoid 110
is excited, the suction piece 111 is rotated, and the suction piece 111 moves within the movement locus of the slide dog 103. Therefore, the suction piece 111 and the slide dog 103 are engaged, and the slide dog 103 returns to the forward position on the control rod 102. Therefore,
The state is now ready for new drilling.

In this way, drilling can be performed by step feeding, but this conventional machine tool requires the solenoid 110 and its peripheral mechanisms to return the slide dog 103 to its original position in front, making the structure complicated. There was a defect that increased in size.

Purpose of the invention The purpose of this invention is to provide a machine tool having a step feed function that eliminates the above-mentioned defects existing in the prior art.

Embodiment Hereinafter, an embodiment in which this invention is embodied in a drilling machine will be described based on the drawings. As shown in FIGS. 1 and 2, a cylinder 2 is fixed to a frame 1 of a drilling machine, and a main shaft cylinder 3 serving as a movable body is inserted through the center of the cylinder 2 so as to be movable back and forth. A contact portion 4 is formed protruding from the outer periphery of the main shaft cylinder 3 near the front, and the piston 5 of the cylinder 2 is fixed to the rear thereof. A main shaft 6 is rotatably supported within the main shaft cylinder 3 so as to be able to move back and forth together with the main shaft cylinder 3, and a chuck device 8 for a drill 7 is attached to the front end of the main shaft 6. A rotating sleeve 9 is connected to the rear end of the main shaft 6 by a key or a spline, and the rotating sleeve 9 is connected to a drive motor 12 via a pulley 10 and a belt 11.

A movement regulating member 13 is loosely fitted into the main shaft cylinder 3, and a screw 14 is cut on the outer periphery of the member. 1
Reference numeral 5 indicates a guide rod for guiding the movement of the movement amount regulating member 13 back and forth. Screw 14 of movement amount regulating member 13
A cylindrical member 16 is screwed into the inner periphery of the cylindrical member 16 through a female thread 17, and a spur gear 18 is formed on the outer periphery of one end of the cylindrical member 16. Spring 19
urges the cylindrical member 16 backward.

A threaded rod 20 is rotatably supported on the frame 1, and a spur gear 21 that meshes with the spur gear 18 is fixed to the outer periphery of the rod. The threaded rod 20 has a pointer 2
2 is screwed together, and the pointer 22 is inserted into the opening 24 of the frame 1 to hold the moving member 23 so as not to rotate, and furthermore, the pointer 22 cooperates with a scale 25. Indicates the moving distance of the main shaft cylinder 3. Reference numeral 33 indicates a knob for rotating the threaded rod 20. When the threaded rod 20 is rotated by the knob 33, the spur gears 21, 1
8, the cylindrical member 16 is rotated to the left or right, and the movement amount regulating member 13 is moved forward or backward, and the movement amount regulating member 13 and the contact portion 4 are moved forward or backward.
The distance between the two is adjusted. On the other hand, the moving member 23 is moved forward or backward by the rotation of the threaded rod 20, and the adjusted interval is indicated by the cooperation of the pointer 22 and the scale 25.

The changeover type first limit switch 26 has an actuator that engages with an operating protrusion 34 on the main shaft cylinder 3, and changes from one position to the other position when the main shaft cylinder 3 moves forward from its original rear position. Can be switched. Always open second limit switch 27
The actuator is in contact with the circumferential surface of the cylindrical member 16, and the circuit is opened when the cylindrical member 16 moves forward.

The details of the above-mentioned structure are described in Japanese Patent Publication No. 56-22642 by the same applicant.

As shown in FIG. 1, there is a first
solenoid switching valves 28 are connected, and the first solenoid switching valve 28 is connected to I
When the cylinder 2 is switched to this position, pressure oil is supplied to the front oil chamber 2a of the cylinder 2, and pressure oil is discharged from the rear oil chamber 2b.
Further, when the first solenoid switching valve 28 is switched to the position, the pressure oil from the front side oil chamber 2a is discharged, and the rear side oil chamber 2b is discharged.
Pressure oil is supplied to the

Further, a throttle valve 30 is connected to the conduit between the first solenoid switching valve 28 and the front side oil chamber 2a of the cylinder 2, and a check valve 31 is connected in parallel with the throttle valve 30.
and a second solenoid switching valve 32 are connected, and the check valve 31 only allows passage of pressure oil from the first solenoid switching valve 28 side, and the second solenoid switching valve 32
is a normally closed type, and is switched to the oven side by excitation, allowing discharge of pressure oil from the front side oil chamber 2a.

As shown in FIGS. 2 and 3, a support arm 41 is fixed to the main shaft cylinder 3, and at the tip of the support arm 41 is a movable rod 42 that extends horizontally to the rear.
is fixed. On the other hand, a support plate 43 is fixed to the frame 1, and mounting plates 44 are attached to both front and rear ends of the support plate 43.
is fixed. Then, the movable rod 4 is guided through a guide hole 45 provided in the upper part of both mounting plates 44.
2 is slidably inserted.

Between both mounting plates 44, a return piece 46 and a pressing piece 47 are mounted on the movable rod 42, each with a screw 4.
A holding pin 50 is attached to the rear surface of the return piece 46, and a pressing bolt 51 is attached to the front surface of the pressing piece 47. In addition, the return piece 46
The forward and backward position of the pressing piece 47 can be adjusted by loosening the screws 48 and 49. A normally closed third limit switch 53 serving as a changeover switch is fixed to the moving rod 42 between the return piece 46 and the pressing piece 47 via a bracket 52. 54 indicates an actuator of the third limit switch 53, and 55 indicates a roller at the tip of the actuator 54, which is close to the pressing bolt 51.

A fixed rod 56 is installed and fixed between the mounting plates 44 below the movable rod 42, and a groove 57 on the lower surface thereof
A key 58 is fitted and fixed to. Fixed rod 56
A rotational biasing body 59 and a stopper 60 are fixed on the top with screws 61 and 62 at intervals in the front and back, and a pair of cam surfaces 6 are provided on the circumferential surface of the rotational biasing body 59.
3 is formed. The rotation biasing body 59 and the stopper 60 can be adjusted in their forward and backward positions by loosening screws 61 and 62, respectively.

Between the rotation biasing body 59 and the stopper 60, a dog body 64 is fitted onto the fixing rod 56 so as to be slidable in the front and rear direction, but not rotatably due to the engagement of the key 58 and the keyway 65. and its dogu 64
The pressing bolt 51 is opposed to the rear surface of the holder.
The dog body 64 has a leaf spring 66 that slides against the lower surface of the key 58, and the resilient contact of the leaf spring 66 with the key 58 holds the dog body 64 in a predetermined sliding position. A slope 67 is formed on the outer periphery of the rear end of the dog body 64. When the moving rod 42 is moved forward, as shown in FIGS. 4 and 5, the roller 55 of the actuator 54 of the third limit switch 53 is moved toward the dog body 64.
After climbing on the circumferential surface of the dog body 64 from the rear surface via the slope 67, the pressing bolt 51
The dog body 64 comes into contact with the rear surface of the moving rod 4.
2 and is moved forward. The third limit switch 53 is opened by climbing onto the dog body 64.

A rotary piece 68 is inserted into the outer periphery of the front end of the dog body 64 so that it can only rotate between an active position and a non-active position, and as shown in FIGS. A protrusion 69 is formed on the rear surface of the return piece 46 so as to be engageable with the other protrusion 69 .
has a holding recess 70 into which the holding pin 50 can fit.
is formed. Then, the rotating piece 68 is moved by the holding pin 50 and the holding recess 70 as shown in FIGS. 3 and 6.
A holding means is configured to hold it in the operating position shown by the solid line in the figure. A spring 71 wound around the dog body 64 is used to always bias the rotating piece 68 in the counterclockwise direction in FIGS. 3 and 6. Further, a stop pin 72 implanted in the dog body 64 is used to hold the rotation of the rotation piece 68 by the spring 71 in a non-active position shown by the two-dot chain line in FIGS. 3 and 6. As shown in FIGS. 4 and 5, two operating protrusions 73 are formed facing forward on the rotating piece 68.
An oblique cam surface 74 facing the cam surface 63 of the rotation biasing body 59 from the rear is formed at its tip. When the moving rod 42 moves forward and the cam surfaces 63 and 74 engage as shown in FIG. 5, the cam action causes the rotating piece 68 to move as shown by the two-dot chain line in FIGS. 3 and 6. The holding recess 70 is rotated from the non-working position to the working position shown by the solid line against the spring 71, so that the holding recess 70 faces the holding pin 50.

Next, the operation of the step feed device constructed as above will be explained with reference to FIGS. 7 to 9. Incidentally, FIG. 7 shows the state when the main shaft cylinder 3 is located at the original position. Now, FIG. 2 shows the state before the drill 7 starts drilling.
In this state, the main shaft cylinder 3 is at the rear end position, the actuator 54 of the third limit switch 53 separates from the dog body 64, the return piece 46 engages with the rotating piece 68, and the return piece 46 engages with the rotating piece 68. The holding pin 50 fits into the holding recess 70 of the rotating piece 68, and the rotating piece 68 is held in the operating position shown by the solid line in FIGS. 3 and 6 against the spring force of the spring 71.

In this state, in order to drill a hole with a depth L shown in FIG. 8, the hole shown in FIG. The knob 33 adjusts the distance between the movement amount regulating member 13 on the main shaft cylinder 3 and the contact portion 4, and when they are engaged, the cam surface 74 of the rotation piece 68 and the cam of the rotation urging member 59 are adjusted. The screw 61 is loosened so that the rotational biasing body 59 is moved back and forth so that it engages with the surface 63, and is adjusted and fixed.

Also, the distance l is the distance between the screw 62 and the screw 48.
is loosened, and the stopper 60, dog body 64, and return piece 46 are adjusted to move together in the moving direction of the moving rod 42, and the position of the slope 67 of the dog body 64 is separated from the roller 55 of the third limit switch 53 by a distance l. screw 62 and screw 4.
It is adjusted by tightening 8.

In this way, when the start switch 81 shown in FIG. 7 is operated to close, the relay 82 and the timer relay 83 are energized. In this case, relay 8
2 is immediately energized and its normally open contacts 82a-8
2c is closed, and the circuits of relay 82 and timer relay 83 enter a self-holding state, but timer relay 83 (trade name: Twin Timer TDA, manufactured by Tateishi Electric Co., Ltd.) is not immediately excited. When the normally open contact 82c is closed, the first and second
The solenoids SOL1 and SOL2 of the solenoid switching valves 28 and 32 are energized, respectively, and the switching valves 28 and 32 are switched to the position. Therefore, pressure oil from the pressure oil supply source 29 is supplied to the rear oil chamber 2b of the cylinder 2, and
Pressure oil in the front side oil chamber 2a is mainly discharged through the second solenoid switching valve 32, and the main shaft cylinder 3 is moved forward together with the main shaft 6 having the drill 7 in rapid traverse. In addition, the normally open contact 82b of the relay 82
When is closed, the relay 84 is energized and its normally open contacts 84a to 84c are closed. For this reason,
The drive motor 12 is started and the main shaft 6 and drill 7 are rotated.

When the main shaft cylinder 3 is moved forward, the movable rod 42 is also moved forward, so the return piece 46 on the movable rod 42
The engagement with the rotating piece 68 is disengaged, so that the holding pin 50 of the return piece 46 is pushed into the holding recess 7 of the rotating piece 68.
0, and the rotating piece 68 is connected to the spring 71.
It is rotated by the spring force to the inactive position shown by the two-dot chain line in FIGS. 3 and 6. Further, as the main shaft cylinder 3 moves forward, the operating protrusion 34 of the main shaft cylinder 3 separates from the first limit switch 26, and the first limit switch 26 is switched from one position to the other position shown in FIG.

Then, when the drill 7 reaches just in front of the workpiece due to the subsequent advancement of the main shaft cylinder 3, the roller 55 of the third limit switch 53 rides on the dog body 64, and the third limit switch 53 is opened. . Therefore, the solenoid SOL2 of the second solenoid switching valve 32 is deenergized and the switching valve 32 is switched to the position. Therefore, the pressure oil from the front side oil chamber 2a of the cylinder 2 comes to pass through the throttle valve 30, and the forward movement of the main shaft cylinder 3 is shifted to low-speed machining feed, and drilling is started in this state.

Immediately after the forward speed of the main shaft cylinder 3 is switched to machining feed, the pressing bolt 51 of the pressing piece 47 engages with the rear surface of the dog body 64.
is slid forward.

Then, as shown in FIG. 8, when a predetermined time _T1 has elapsed, the timer relay 83 is energized, its normally closed contact 83a is opened, and the first solenoid switching valve 28 is switched to the position. Therefore,
The pressure oil from the pressure oil supply source 29 is checked by the check valve 31.
Pressure oil is supplied to the front side oil chamber 2a of the cylinder 2 through the cylinder 2, and the pressure oil in the rear side oil chamber 2b is discharged.
The main shaft cylinder 3 moves to rapid retraction together with the main shaft 6, and the moving rod 42 retreats. In this case, since the rotating piece 68 is placed in the inactive position as shown by the two-dot chain line in FIGS. 3 and 6, the returning piece 46 returning to the rear will not collide with this rotating piece 68. There isn't.

When the moving rod 42 moves backward, the third limit switch 53 first separates from the dog body 64 and the third limit switch 53 is closed. Then, as shown in FIGS. 8 and 9, when a time T ₂ shorter than the advance time T ₁ has elapsed, the timer relay 83 is again demagnetized and its normally open contact 83a is closed. Solenoid SOL1 of the second solenoid switching valve 28, 32,
SOL2 is energized and its valves 28, 32 are switched to their respective positions. Therefore, as described above, the main shaft cylinder 3 moves rapidly forward.

In this case, the position where the dog body 64 was moved forward by the pressing bolt 51 in the previous process,
That is, since the pressing bolt 51 is in the position where it has moved from forward to backward, the actuator 54 of the third limit switch 53 rides on the dog body 64 just before the drill 7 reaches the bottom of the previous drilling, and the third limit switch is activated. 53 is opened, and the forward movement of the main shaft cylinder 3 is switched to low-speed machining feed. Thereafter, when the pressing bolt 51 comes into contact with the dog body 64, the drill 7 reaches the bottom of the hole, and the hole continues to be drilled, and the dog body 64 is also slid forward. When the predetermined time _T1 has elapsed in this manner, the timer relay 83 is excited and the main shaft cylinder 3 shifts to rapid retraction.

As described above, the step feed is repeated and drilling is performed intermittently. When the drill 7 drills a hole by a predetermined length L and the main shaft cylinder 3 reaches the forward end position, the contact portion 4 on the main shaft cylinder 3 shown in FIG. The cylindrical member 16 is moved forward against the spring force of the spring 19. Therefore, the second limit switch 27 is opened and the relay 82 is demagnetized, and the power supply to the timer relay 83 is cut off, and the normally open contact 82 of the relay 82 is cut off.
A to 82c are opened, and the function of timer relay 83 is disabled. Therefore, the first and second
The solenoid switching valves 28 and 32 are switched to their respective positions, and the main shaft cylinder 3 shifts to rapid retraction.

On the other hand, when the spindle cylinder 3 reaches the forward end position, as is clear from FIG. 5, the cam surface 63 of the rotation biasing body 59 and the cam surface 74 of the rotating piece 68 are engaged with each other, and the rotating piece 68 is pulled by the spring 7 due to the cam action of these.
3 and 6 against the spring force of the spring 68, so that the protruding portion 69 of the pivot piece 68 faces the rear surface of the return piece 46.

Therefore, as the main shaft cylinder 3 retreats, the return piece 46
When the moving rod 42 moves back, the return piece 4
6 engages with the rotating piece 68, and the holding pin 5
0 is fitted into the holding recess 70, and the rotating piece 68 is held unrotatable. Therefore, the rotating piece 68
The rotating piece 68 and the dog body 64 are moved rearward together with the moving rod 42 while being held in the operating position shown by solid lines in the figures and FIG.

When the main shaft cylinder 3 returns to its original rear position and the dog body 64 and rotating piece 68 return to the position shown in FIG. 2, the first limit switch 26 is switched back to the position shown in FIG. is demagnetized, the drive motor 12 is stopped, and the rotation of the drill 7 is stopped. In this way, one cycle of drilling work is completed. As is clear from the above explanation, in this machine tool, the moving rod 42
As the dog body 64 returns to its original position, the dog body 64 is returned to its original position by the engagement between the return piece 46 and the rotating piece 68. There is no need for a solenoid or its surrounding mechanisms. Therefore, with this machine tool, it is possible to avoid increasing the size and complicating the mechanism.

In addition, as in this embodiment, a movable rod 42 is supported on the main shaft cylinder 3 via a support arm 41, and a support plate 43 is attached to the frame 1, and a step feed is controlled on the movable rod 42 and the support plate 43. By providing a mechanism for this purpose, the step feed function can be added to an ordinary machine tool that does not have the step feed function by attaching it as a unit.

Note that this invention is not limited to the above embodiment, and contrary to the above embodiment, the return piece 46, the third
The limit switch 53 and the pressing piece 47 are attached to the fixed rod 56 side, and the rotational biasing body 59,
The dog body 64 and the stopper 60 may be attached to the movable rod 42 side.

Effects of the invention As exemplified in the embodiments above, this invention provides a moving rod that reciprocates integrally with the moving body,
On either the moving rod or the frame,
A slidable dog body that supports the rotating piece and a rotational bias that rotates the rotating piece from the inactive position to the active position by cam action when the moving body is moved to the forward end position. A switch is provided on the other side of the movable rod or frame to engage with the dog body to switch the movable body to rapid processing feed, and a press to slide the dog body when the movable body moves forward. and a return piece for returning the dog body to its original position when the movable body moves back, and further, between the return piece and the rotating piece, the engagement between the returning piece and the rotating piece is released. By providing the holding means for holding the rotary piece in the operating position until it is turned, the structure can be simplified and the size can be reduced, which is an excellent effect.

[Brief explanation of the drawing]

Figures 1 to 9 show an embodiment of a machine tool embodying this idea, with Figure 1 being a simplified diagram showing the whole, and Figure 2 being a partially cutaway front view showing the main parts. , FIG. 3 is a cross-sectional view taken along the line -- in FIG. 2, FIGS. 4 and 5 are front views showing the third limit switch portion during forward movement and at the end of forward movement, respectively, and FIG. 6 is a cross-sectional view of FIG. 7 is an electric circuit diagram, FIG. 8 is a line diagram showing the step feed process, FIG. 9 is a time chart showing the relay and timer relay excitation time, and FIG. 10 is a sectional view showing a conventional machine tool. Frame...1, Main shaft cylinder...3, Moving rod...4
2. Return piece...46, Pressing piece...47, Holding pin...50, Third limit switch...53, Rotation biasing body...59, Cam surface...63, 74, Dog body...64 , Rotating piece...68, Holding recess...7
0, Spring...71.

Claims (1)

[Claims for Utility Model Registration] Mobile body 3 supported by frame 1 in a reciprocating manner
After moving forward with rapid traverse, switch to machining feed and perform the machining work, and during the machining work, the moving body 3 is once moved backward and then moved forward again so that the machining work is divided into multiple times. , a machine tool having a step feed function that returns the movable body 3 to its original position at the end of machining, comprising: a movable rod 42 connected to the movable body 3 and reciprocated together with the movable body 3; A dog body 64 is supported on either the movable rod 42 or the frame 1 so as to be slidable in the direction of movement of the movable rod 42, and a dog body 64 is attached to the other of the movable rod 42 or the frame 1, and is attached to the other of the movable rod 42 or the frame 1 to prevent the forward movement of the movable body 3. A changeover switch 53 that is operated by engaging with the dog body 64 when the movable body 3 moves forward, and is installed on the same side as the changeover switch 53 in the vicinity of the changeover switch 53 to switch to machining feed by rapid forwarding. After the switch 53 engages with the dog body 64, a pressing piece 47 is engaged with the dog body 64 to slide it in one direction, and is disengaged from the dog body 64 when the movable body 3 moves back. and is supported on the dog body 64 so as to be only rotatable between an active position and a non-active position, and is always supported by a spring 71.
The rotating piece 68 is held in the inactive position by the action of
It is attached on the same side as the dog body 64, and when the movable body 3 is moved to the forward movement end position, it engages with the rotary piece 68 and applies a spring force to it by the action of the cam surfaces 63 and 74. A rotation urging member 59 is provided on the same side as the pressing piece 47 to rotate the pressing piece 68 from the non-working position to the working position against the force, and the rotating piece 68 is placed in the non-working position during the machining operation. When the movable body 3 is moved back once while it is in the arranged state, it does not engage with the rotating piece 68 in its inactive position,
When the movable body 3 is moved back with the rotary piece 68 being rotated to the operating position at the end of machining,
As the movable body 3 moves back, the rotary piece 6 moves to the operating position.
8, and the dog body 6 through its rotating piece 68.
A return piece 46 is provided between the return piece 46 and the rotating piece 68 to prevent the rotating piece 68 from returning to the inactive position when they are engaged. After the dog body 64 is returned to its original position, the movable body 3 is moved forward for the next machining operation and rotated until the return piece 46 and the rotation piece 68 are disengaged. A machine tool having a step feed function, comprising holding means 50, 70 for holding the piece 68 in the working position.