JPS6125930Y2 - - Google Patents

Description

[Detailed description of the invention] Technical field This invention is a machine tool that has a step feed function that allows the work to be performed in multiple steps by reciprocating the tool multiple times, instead of performing operations such as cutting and drilling to a required length all at once. This invention relates to a drill unit that has been improved so that it can enter a smooth operating state immediately after startup.

Conventional technology A conventional step feed device detects when the torque applied to the spindle exceeds a predetermined value, moves the spindle cylinder backwards, and then moves it forward again. In a drill unit that is stopped and then rotated again when the main shaft cylinder moves forward to start the next machining, when the motor starts rotating to start the next machining, the start-up torque may increase, especially if there is a gear transmission mechanism, etc. Because the torque detection means is activated immediately and detects torque,
The main shaft cylinder is reciprocated several times until the motor is rotated at full speed, and the tool is reciprocated even though no machining is being done, resulting in unnecessary movement.

Purpose This idea was created in view of the above,
An object of the present invention is to provide a drill unit equipped with a step feed function, which disables detection by a torque detection means until the motor is rotated at full speed at the beginning of reciprocation of the main shaft cylinder at the start of machining work. . That is, during machining work, the main spindle cylinder is reciprocated by switching the air supply to the air cylinder, and the switch to reciprocal movement is detected by the torque detection means when the torque applied to the main spindle exceeds a set value. In a drill unit that step-feeds the main shaft cylinder, there is provided a means for stopping the reciprocation of the main shaft cylinder or regulating it to an extremely low speed when the motor starts rotating at the time of startup, and disabling the torque detection means while this means is operating. This is a drill unit equipped with means for

Embodiment Next, embodiments of this invention will be described based on the drawings. Reference numeral 1 denotes a long and narrow case in which a main shaft 12 and a piston rod 22 are arranged parallel to each other, and the space between the transverse partition wall 2 and the end face plate 3 at the front end can be sealed. 4 are provided in one piece. The main shaft 12 is driven by a motor 27 attached to the rear end of the case 1, and a spline 13 is provided on the outer periphery of the front end. Reference numeral 14 denotes a main shaft cylinder that freely surrounds the main shaft 12, and is tightly passed from the partition wall 2 into the center of the air cylinder 9, which is constituted by the cylinder 8 whose both ends are fitted to the partition wall 2 and the end plate 3.
A piston 15 that contacts the inner surface of the cylinder 8 is formed at the front end, and an extended main shaft cylinder 16 whose front end tightly projects from the end plate 3 is fixed to the front side of the piston 15 by external fitting.

The main shaft cylinder 1 is attached to the outer periphery of the spline 13 of the main shaft 12.
4 and the rotating body 1 located at the center of the extended main shaft cylinder 16.
8, to which an internally toothed engaging body 19 that engages with the spline 13 is fixed, and a tapered shaft 20 supported at the front end through a bearing 17 on the inner periphery of the front end of the extended main shaft cylinder 16. The rotating body 18 connects the outer periphery of the rear end to the main shaft cylinder 14 via a suitable rotating insulator 21.
engages the front end of the This rotating body 18 is connected to the main shaft cylinder 14
While reciprocating together with the extended main shaft cylinder 16, rotation is transmitted from the main shaft 12 to rotate the tapered shaft 20. The front side of the piston rod 22 is inserted into a cylinder chamber 11 constituted by a cylindrical body 10 which is rotatably fixed with its front and rear ends penetrating the end plate 3 and the partition wall 2 in an oil-tight manner. The piston rod 22 has its rear end passed through a one-way clutch 71 provided in the case 1, and its rear end protrudes to the outer periphery of the case 1. Attach the removable cover 95. The piston rod 22 is made of a pipe, and is rotatably fitted tightly from the front end of the cylindrical body 10, centered around a spring 23 whose front end is engaged with a filter plate made of a sintered metal plate provided on the inner ring surface of the oil passage structure 54. The rear end of the spring 23 is locked by a screw plug 24 provided at the rear end.

A gear chamber 5 is provided in the case 1 corresponding to the rear end of the main shaft 12, a replacement window 6 is opened on the side, and a sliding hole 7 is opened at the rear side of the gear chamber. A driven gear 25 is fitted into the rear end of the main shaft 12 within the gear chamber 5.

A motor 27 and a shaft support disk 35 are fixed to the rear end surface of the case 1 by several pin shafts 26 protruding from around the sliding hole 7, and a cap is attached to the shaft support disk 35. Fix 38. Said motor 2
7 is a normal type, and the front end of an output shaft 29 protruding from the rotor 28 is pivotally supported by a bearing in a bearing case 31 slidably provided in the sliding hole 7, and its output is A driving gear 30 facing into the gear chamber 5 is fixed to the front end of the shaft 29, and the bearing case 31 is provided with a projecting piece 32 that projects laterally along the rear end surface of the case 1. A shaft 33 protrudes from the rear end of the rotor 28 and is supported by a bearing 37 in a bearing case 6 slidably slidable at the center of a shaft support disk 35. A disk 34 whose rotation is insulated by a bearing is fitted behind the disk 35.

A sliding tube 39 shown in FIGS. 3 and 4 is attached to the rear side of the center portion of the cap 38, and a long detection hole 40 is provided in the axial direction and a scale 41 is provided on the sliding tube 39, and a protrusion with a base line 44 is provided inside. The part 43 is fitted into the detection hole 40 and the indicator plate 42 which is prevented from rotating is fitted. 28
Hang both ends of the pressure spring 45 that presses. Sliding tube 39
A feed screw 46 with a handle is attached to the rear end so that it can rotate freely, and the feed screw 46 is screwed into the center of the indicator plate 42 described above.

Reference numeral 47 denotes a gear support piece that is fixed to the outside of the replacement window 6 and projects the shaft support 48 into the gear chamber 5. A first transmission gear 49 that meshes with the main drive gear 30 is supported on one side of the shaft support 48. A second transmission gear 51 that meshes with the first transmission gear 49 is fixed to one end of a transmission shaft 50 that is pivotally supported through the shaft support 48, and a third transmission gear 51 that meshes with the driven gear 25 of the main shaft 12 is fixed to the other end. The transmission gear 52 is fixed.

Main drive gear 30, first to third transmission gears 49, 5
1, 52 and the driven gear 25 are all helical gears. In addition, several types of gear support pieces 47 with different gear ratios of the first to third transmission gears are prepared and replaced with any one, thereby changing the rotation speed of the main shaft 12.

The outer periphery of the cylinder 8 and the cylindrical body 10 is the case 1 and the partition wall 2.
and an oil tank oil sump chamber 5 surrounded by an end plate 3 and an end plate 3.
Set it to 3. The oil passage structure 54 fitted from the front end of the cylindrical body 10 communicates with the oil tank 53 through a one-way valve and a variable throttle oil passage.

Further, a through hole 57 is bored in the partition wall 2 of the case 1, parallel to the main shaft cylinder 14 and facing the side surface of the piston 15.
A crinkle 59 having an annular groove 58 serving as an empty passage on the outer periphery is tightly fitted into this hole with its opening facing the piston 15 side. The cylinder 59 has a piston 1
A blind hole 61 and an air window 6 that form an air passage with the 5th side closed.
The valve cylinder 60 in which the spring 2 is bored is blocked, and the spring 6
3, it is constantly urged to protrude to a certain position. The protruding end of this valve cylinder 60 is the cylinder 15.
While the cylinder 5 protrudes by a specified amount while touching
When the piston 15, that is, the valve cylinder 60, moves forward by a specified amount, the air passage is opened, and the annular groove 58, the air window 64, and the blind hole are closed. 61, the air window 62, and the forward movement side chamber of the cylinder 9 communicate as a main path. Furthermore, an air supply passage 65 and a throttle hole 6 are provided toward the annular groove 58.
6 is bored, and a needle valve 67 is inserted into this throttle hole 66 to form a variable throttle. Further, the throttle hole 66 is provided with an air passage 68 which is perpendicular thereto and communicates with the forward movement side chamber of the cylinder 9, and the passage 68 and the throttle valve 66 form a side passage.

The one-way clutch 71, as shown in detail in FIG. It consists of a base body 75 to be pressed. A taper 76 is formed on the inner surface of the base body 75 and extends toward the cylinder chamber 11 and contacts the ball 73 . This one-way clutch 71 allows the piston rod 22 to move freely in the direction of the cylinder chamber 11, that is, in the forward direction, but prevents it from moving in the backward direction. However, the base 75
When the cylinder rod 22 is pushed against the elasticity of the spring 74, the cylinder rod 22 is free to move in the backward direction.

77 is tightly fitted to the rear end of the main shaft cylinder 14, and the fork-shaped portion 78
The control arm is fitted on both sides of the piston rod 22 of the one-way clutch 71 and corresponds to the distal end surface of the base body 75 of the one-way clutch 71, and in the original position of FIG. A means is provided for disabling the clutch 71. This control arm 7
7 is provided with a pressing protrusion 79 (FIGS. 1 and 9).

80 is fitted onto the piston rod 22 to form a forked portion 8.
1 fitted on both sides of the main shaft cylinder 14,
When the control arm 77 moves forward together with the main shaft cylinder 14, it contacts the engaging piece 80 and carries the piston rod 22 in the same direction. The engaging piece 80 is provided with a projecting arm 82 (first, ninth
figure).

As shown in FIG. 9, a first switch chamber 83 is provided on the side of the gear chamber 5 of the case 1, and limit switches Ls-2 and Ls-3 are mounted therein. The limit switch Ls-2 is turned on by being pushed by the actuation pin 84 that protrudes from the protrusion 32 of the bearing case 31 into the first switch chamber 83. Further, a sliding rod 85 whose one end corresponds to the pressing protrusion 79 of the control arm 77 projects into the first switch chamber 83 .
The sliding rod 85 corresponds to the opening/closing control piece x of Ls-3 as shown in FIG. The sliding rod 85 is pressed and continues to turn on the limit switch Ls-3, but when it is no longer pressed, it moves to the left in the figure by the elasticity of the spring 86 and turns off the limit switch Ls-3. .

The case 1 includes a dog operating chamber 8 in which the protruding arm 82 of the engagement piece 80 protrudes over the operating range of the protruding arm 82.
7 and a second switch chamber 88 as shown in FIGS. 9 and 10, and a sliding rod 89 that operates across both chambers.
A first dog 90 and a second dog 91 that abut against the protruding arm 82 are fixed to the sliding rod 89 on both front and rear sides of the protruding arm 82 in the dog operation chamber 87. The first dog 90 is a projecting arm 82 provided on the engagement piece 80 of the piston rod 22 which is pushed back in the backward direction by the spring 23.
The second dog 91 is a tool (drill) 96 attached to the tapered shaft 20 via the chuck 20a.
Since this determines the most advanced position of the slider, these can be moved and adjusted on the sliding rod 89. A cam 92 corresponding to the limit switch Ls-1 in the second switch chamber 88 is fixed to the sliding rod 89.
Ls-1 has a normally closed contact a and a normally closed contact b as shown in FIG.
When pressed, contact a opens and contact b closes.
A cover 93 is provided in the dog operation chamber 87, and a long hole 94 is formed in the cover 93, and a scale is provided on the hole line. 1st・
The movement of the second dogs 90 and 91 can be adjusted through the elongated hole 94.

The operation of the embodiment described above will be explained with reference to the wiring diagram of FIG. 11. As shown in Fig. 1, when the main shaft cylinder 14 is stopped at the home position and the piston rod 22 is in the most retracted position, when the start switch ST shown in Fig. 11 is pressed, the relay CR1 is activated and the normally closed contact a of LS-1 is activated. Close the inserted holding circuit and the circuit of relay CR3 whose contacts are inserted into the motor circuit, and at the same time close the sliding rod 8.
Limit switch Ls-3 activated by pressing 5
Drives the relay CR2 with Ls-2 inserted in parallel and the drive solenoid SOL of the pressurized air supply switching valve.
Therefore, the motor 27 is started, and at the same time pressurized air is supplied to the air cylinder 9 from the supply path 65 so as to reciprocate the piston 15 and the main shaft cylinder 14 in the forward direction. Since the main passage is closed by the valve cylinder 60, the air passes through the annular groove 58 and is throttled by the throttle hole 66, leading to the passage 68.
It flows into the cylinder 9 from the side passage, and the piston 15 is moved forward at an extremely low speed. With this forward movement of the piston, the valve cylinder 60 is pushed out by the elasticity of the spring 63. During this time, the opening/closing control piece of Ls-3 is pressed by the sliding rod 85, turning on and disabling Ls-2, so the motor rotation is low and the rising torque is large due to the gear system, so it is not used for torque detection. Despite the limit switch Ls-2 being turned on. The drive solenoid SOL continues to operate and the supply to the air cylinder 9 is not switched. Therefore, the piston 15 continues to move forward at an extremely low speed, and the valve cylinder 60
The air window 64 of the cylinder 59 is opened only when the cylinder 59 protrudes by a specified amount, and the air flows through the annular groove 58 and the air window 6.
4. It flows into the cylinder 9 through the main path of the blind hole 61 and the air window 62. The main shaft cylinder 14 rapidly moves forward at the speed of the piston 15 until the control arm 77 collides with the engagement piece 80 of the piston rod 22, and after that collision, the oil sucked into the cylinder chamber 11 passes through the variable throttle. It is braked by the amount discharged into the tank 53 and changes to cutting feed. At that time, tool 96 contacts the workpiece and begins drilling. During the cutting process, the cutting torque of the spindle 12 gradually increases,
When the pressure set in the pressure spring 45 is exceeded, the thrust force of the helical teeth causes the first transmission gear 49 and the main shaft gear 3 to
0 and axial sliding occurs. However, since the first transmission gear 49 is made immovable in the axial direction, the main drive gear 30 moves in a direction against the elasticity of the pressure spring 45 along with the output shaft 29 and the rotor 28. Therefore, the bearing case 31 also moves in the same direction, and the Ls-2 by the operating pin 84 of the protrusion 32
Release the pressure to turn it off. On the other hand, when the main shaft cylinder 14 and the control arm 77 move forward by a specified amount in the forward direction as described above, the pressing of the sliding rod 85 by the pressing protrusion 79 is released and the sliding rod 85 is pushed out by the spring 86.
Ls-3 immediately after driving the drive solenoid SOL
Since it is operating with OFF, Ls−
At the same time when solenoid 2 is turned off, relay CR2 and drive solenoid SOL are deactivated, causing a switching operation in the pressurized air switching valve to supply pressurized air to the air cylinder 9 to push the piston 15 back in the backward direction.
Since the motor 27 continues to rotate at this time, the tool 96 is rotated by the main shaft 12 and the rotating body 18 and moves in the direction of exiting the hole. Therefore, the torque of the main shaft 14 immediately decreases, and the rotor 28
With a slight advance such as this, Ls-2 returns to on operation.
However, at that time, relay CR2 is not driven as described above, so Ls-2 connected in series with the contact of the relay does not drive drive solenoid SOL.

As mentioned above, the pressure spring 45, operating pin 84, limit switches Ls-2, Ls-3, etc. are connected to the main shaft 12.
This is an example of a step feed control means that moves the main shaft cylinder 14 backward every time the cutting torque applied to the shaft reaches a predetermined value, and moves the main shaft cylinder 14 forward again during the backward movement.

On the other hand, in the one-way clutch 71, the control arm 77 moves forward from the origin as described above, and at the same time, the pressure on the base body 75 is released and the taper 76 presses the ball 73 as shown in FIG. 7, so that the piston rod 22 moves forward (forward movement). However, as mentioned above, the main shaft cylinder 14 along with the tool 96 is
Even if the control arm 77 moves backward (returns), the piston rod 22 stops without moving back due to the action of the spring 23, and the engagement piece 80 is stopped at a slightly forward position.

The main shaft cylinder 14 returns to its original position immediately before the sliding rod 8
Press 5 and turn on Ls-3 to turn on relay CR.
2. Drive the drive solenoid SOL to advance the piston rod, main shaft cylinder 14, etc. in the forward direction again, and advance at the speed of the piston 15 until the control arm 77 collides with the engagement piece 80 in the forward position, and engages. piece 80
After hitting the cylinder chamber 1 again as described above.
Cutting feed is performed by braking according to the oil discharge speed of step 1. This position is the position where the tool 96 again hits the far end of the hole that has retreated beyond the torque set in the pressure spring 45, and at this point, the tool 96 starts drilling again and the cutting torque exceeds the set value. Then, the hole is deepened one by one by repeating the forward movement and the backward movement, and when the hole is formed to the required depth and the main shaft cylinder 14 reaches the forward most forward position. The protruding arm 82 provided on the engagement piece 80 of the piston rod 22 hits the second dog 91 to move the sliding rod 89 in the forward direction, thereby closing the normally closed contact a of Ls-1.
Open, detect the most advanced position, and turn on relay CR1/CR.
2. Deactivate both drive solenoids SOL. At the same time, normally open contact b is closed and the relay
The drive of CR3 is maintained in place of the contact of relay CR1, and the drive of motor 27 is continued.

When the drive solenoid SOL is not driven, the piston 15 is finally moved back in the backward direction by the air cylinder 9, but at this time, Ls-2 and Ls-
3 is turned on as described above, the drive solenoid SOL is not driven, and the main shaft cylinder 14 returns to its original position and the control arm 77 pushes the base body 75 of the one-way clutch 71 to disable the clutch action. Therefore, the piston rod 22 moves back and forth for the first time due to the elasticity of the spring 23, and the protruding arm 82 hits the first dog 90, and the cam 92 moves the sliding rod 89 into the second switch chamber 88.
Retract the cam 92 until it engages the inner wall of the Ls
Remove from -1. Therefore, the normally closed contact a is turned back on, the normally closed contact b is turned off, the relay CR3 is deactivated, the motor 27 is stopped, and one cycle of the process is completed. The piston rod 22 is the first dog 90
When the piston 15 returns to its original position, the valve cylinder 60 is pushed back and the main air passage is closed. Therefore, at the end of the backward movement of the piston 15, the air in the forward movement side chamber of the air cylinder 9 is discharged through the side passage, so that after the backward movement of the piston 15 is relaxed, the piston 15
is returned to its original position.

FIG. 12 is a diagram illustrating the above-mentioned step feed operation, and the double line indicates extremely low speed feeding of the piston 15 of the air cylinder due to blockage of the main air path.
Thin lines indicate fast forwarding and fast reversing depending on the speed of piston 15 of the air cylinder, thick lines indicate piston rod 2.
2 indicates cutting feed with limited feed speed.
Ls-2 is a signal member that converts the cutting feed of each stage to quick return, Ls-3 is a signal member that converts to quick return,
Ls-1 is a signal member that switches from the final forward position to the original position at the time of the final cutting feed, and its operation is as described above.
In this embodiment, the main shaft cylinder is moved forward at an extremely low speed at the start of work, but it is also possible to temporarily stop the work and achieve the objective by using a timer, a current relay, or other means.

Effects As detailed above, step feed is performed by switching the supply of pressurized air to the air cylinder depending on the magnitude of the cutting torque. Pressurized air is directly flowed into the cylinder at the beginning of the machining operation of the drill unit. Instead, the piston is moved forward at an extremely low speed by letting it flow through the side passage through the throttle,
During this period, the torque detection means was temporarily disabled, and then the main path was opened to allow rapid forward movement, so the main shaft was reciprocated due to the activation of the torque detection switch due to the large start-up torque at startup when the motor rotation was low. It has become possible to prevent the vibration phenomenon that causes This eliminates unnecessary movement of the main shaft cylinder and allows necessary operations to be performed accurately. This has the effect of alleviating worker anxiety and improving reliability.

[Brief explanation of the drawing]

The attached drawings show an embodiment of this invention, and FIG. 1 is a longitudinal sectional side view of the main shaft cylinder 14 in its original position;
FIG. 2 is a longitudinal sectional side view showing the state in which the main shaft cylinder 14 changes from rapid feed to cutting feed. Figure 3 shows the sliding tube 39.
4 is an enlarged sectional plan view of the sliding tube 39 and the like, and FIG. 5 is an enlarged longitudinal sectional side view of the valve tube 60. 6 is a sectional view taken along the line A-A in FIG. 5, FIG. 7 is an enlarged vertical sectional side view of the one-way clutch 71, FIG. chamber 83, dog operation chamber 87 and second switch chamber 8
FIG. 10 is a partially cutaway side view of the dog operation chamber 87 and second switch chamber 88, FIG. 11 is a wiring diagram, and FIG. 12 is a step feed operation diagram. . 1... Case, 2... Partition wall, 3... End plate, 9
...Air cylinder, 11...Cylinder chamber, 12
... Main shaft, 14 ... Main shaft cylinder, 15 ... Piston,
18... Rotating body, 22... Piston rod, 23
... Spring, 27 ... Motor, 53 ... Oil tank,
54...Oil passage structure, 59...Cylinder, 58
... annular groove, 60 ... valve barrel, 62, 64 ... air window, 63 ... spring, 66 ... throttle hole, 67 ... needle valve, 71 ... one-way clutch, 73 ... ball,
74...Spring, 75...Base, 76...Taper,
77... Control arm, 80... Engagement piece, 82... Projection arm, 96... Tool.

Claims (1)

[Claims for Utility Model Registration] From the driving body 27 to the power transmission mechanism 25, 30, 4
9, 51, 52 and a tool 96 at one end.
a main shaft 18 having a main shaft 18; and a main shaft cylinder 1 that rotatably supports the main shaft 18.
an air cylinder 9 for reciprocating the main shaft cylinders 4 and 16 along the axial direction together with the main shaft; . When the main shaft cylinders 14, 16 reach the most advanced position, or when the detection means detects that a predetermined torque or more is applied to the main shaft, the direction of supplying air to the air cylinder 9 is switched and the main shaft cylinders 14,
In the drill unit, the main shaft is rotated at full speed at the beginning of forward movement of the main shaft cylinders 14 and 16 at the start of machining, until the driving body 27 rotates at full speed. Cylinder 14,
A drill unit comprising means for stopping or reciprocating the torque detecting means at an extremely low speed, and disabling means for disabling the action of the torque detecting means at least while the means is in operation.