JPH018247Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a deep hole drilling device that drills a deep hole by repeatedly operating a drill while increasing the feed rate in stages.

(Prior art) For example, when drilling deep holes such as oil holes in the crankshaft of an engine using a processing machine as shown in Japanese Patent Application Laid-Open No. 55-5207, chips may be generated during processing. There is a problem that the drill gets stuck in the hole and prevents the drill from moving forward, so once the hole has been drilled to an appropriate depth, the drill should be returned to its original position, and after removing any chips in the hole, the drill should be inserted again to drill further. A method is used in which the drill is repeatedly fed while increasing the feed amount in stages.

However, such a hole drilling method requires extra time to retreat the drill from the intermediate drilling position and then to advance the drill to the intermediate drilling position. Therefore, in this type of device for drilling deep holes, the retracting speed of the drill is increased, and the forward speed can be switched between high and low speeds, so that the forward feed of the drill to the previously drilled position is performed at high speed. It is configured as follows. In addition, when performing forward feed at this high speed, there is a risk of damaging the tip of the drill if it comes into contact with the bottom of the previously drilled hole at high speed, so feed at low speed slightly before the previously drilled position. It is controlled to switch to

However, conventional deep hole drilling equipment has a configuration in which the feed rate is controlled using complicated electrical devices and circuits as described above, and therefore frequently breaks down, and when a fault occurs, it is not possible to immediately repair it on site. It had the following drawbacks and maintenance problems.

(Purpose of the invention) In view of the above-mentioned conventional circumstances, the present invention is designed to control the feed rate as described above in a deep hole processing device with a mechanically simple structure, and has excellent maintainability. It is an object of the present invention to realize a deep hole machining device that can perform the above control reliably and with high precision.

(Structure of the invention) The deep hole processing device according to the invention is structured as follows in order to achieve the above object.

That is, it has a drill unit that has a drill and a motor that rotationally drives the drill, and a feed device that is made of a hydraulic cylinder or the like that moves the drill unit forward and backward and that can switch the forward speed between high and low speeds. In the deep hole drilling device in which the drill unit is repeatedly fed while increasing the feed amount in stages, the drill unit is composed of a piston rod and a cylinder case, and is contracted by engaging with the drill unit when the drill unit moves forward. A feed amount storage mechanism that stores the stepwise advance position of the unit as its contraction stop position, and a feed amount storage mechanism that is provided on the drill unit side of the engagement portion between the feed amount storage mechanism and the drill unit and stores the feed amount when engaged. A detector is provided in contact with the mechanism side, and a detector is provided on the feed amount storage mechanism side to face the detector, and normally a spring projects a predetermined amount from the contact surface of the contact member on the feed amount storage mechanism side toward the detector side. a speed switching position setting member that contacts the detector at a position in front of the drill unit by the above-mentioned protrusion amount when the drill unit re-engages with the feed amount storage mechanism when the drill unit moves forward again; and a protrusion of the speed switching position setting member. an adjustment mechanism that finely adjusts the amount, a sliding force applying mechanism that applies a sliding force greater than the spring force between the piston rod and the cylinder case, and an output from the detector when the speed switching position setting member comes into contact with the A feed control device is provided which switches the forward speed of the drill unit by the speed device from high speed to low speed based on the detection signal, continues the low speed feed operation for a certain period of time, and switches the drill unit to backward operation after the elapse of the said time.

According to such a configuration, when the drill unit moves forward again, the speed switching position setting member and the detector come into contact with each other, and the feed rate of the unit is moved forward by the protrusion amount of the speed switching position setting member from the previous drilling position. In this case, the speed position setting member and the detector face each other in the direction of movement of the drill unit and come into contact with each other.
The position of the unit will be directly detected,
Further, since the amount of protrusion can be finely adjusted by the adjustment mechanism, the speed switching position of the drill unit can be controlled reliably and with high precision. In addition, a sliding force applying mechanism applies a sliding force greater than the spring force that biases the speed switching position toward the detector between the piston rod and the cylinder case that constitute the feed amount storage mechanism. Even if there are variations in the spring force, the detector will operate reliably at a position a predetermined amount before the previous drilling position, ensuring reliability of control.

(Example) Hereinafter, the deep hole drilling apparatus of the present invention will be explained based on the example shown in the drawings.

As shown in FIG. 1, the deep hole drilling device 1 has a drill unit 10 installed on a base 2 so as to be slidable back and forth, and a feed device 20 provided inside the base 2 as main components. The drill unit 10 has a main shaft 12 rotatably supported in a main shaft case 11, and a drill 14 connected to the front end of the main shaft 12 protruding from the main shaft case 11 via a chuck mechanism 13. There is. The belts 16, 16, intermediate shaft 17,
The main shaft 12 or the drill 14 are rotationally driven through gears 18, 18.

On the other hand, the feeding device 20 is connected to the drill unit 1.
Cylinder 2 arranged parallel to the sliding direction of 0
1 and a piston 2 fitted into the cylinder 21
2, and a piston rod 23 whose tip end is fixed to the piston 22 and extends rearward from the rear end of the cylinder 21, and the rear end of the rod 23 is connected to the drill unit 10 via a connecting member 24. is connected to case 11 of. The cylinder 21 has a pipe 25 that communicates with the advancement chamber 21a behind the piston 22 through a through hole 21a', and a piston
The piston rod 22 is connected to a pipe 26 leading to a backward chamber 21b in front of the piston 22, and the piston 22 is slid by supplying and discharging hydraulic oil from these pipes 25 and 26 to the forward chamber 21a and the backward chamber 21b. The drill unit 10 is slid back and forth on the base 2 via the connecting member 23 and the connecting member 24. Further, a stopper shaft 27 is installed on the base 2 along the piston rod 23, and the shaft 27 is inserted into a hole 24a formed in the connecting member 24, so that when the drill unit 10 moves forward to a predetermined position, the stopper shaft 27 is inserted into the hole 24a. axis 27
The forward movement of the drill unit 10 is restricted by the connection member 24 coming into contact with the large diameter portion 27a at the tip of the drill unit 10. The positional relationship of the stopper shaft 27 with respect to the base 2 can be adjusted by loosening the lock nut 28, whereby the forward movement restricting position of the drill unit 10 can be arbitrarily set.

As shown in FIG. 2, a forward end detection switch 29 and a backward end detection switch 30 of the drill unit 10 are provided at the front and rear portions of one side of the base 2, respectively. At predetermined positions on the side surface of the spindle case 11, two abutting members 31 and 32 are juxtaposed front and back and protrude, as shown in the figure, to support the drill unit 1.
If 0 is located at the backward end, the rear contact member 32
The backward end detection switch 30 is made conductive, and the forward end detection switch 29 is made conductive by the front abutting member 31 when the drill unit 10 advances a certain stroke from the position shown. Here, the position of the drill unit 10 where the forward end detection switch 29 is turned on is set to the front side of the position where the forward movement is restricted by the stopper shaft 27.

In addition to the above configuration, this deep hole machining apparatus 1 is provided with a feed amount storage mechanism 40 for the drill unit 10. This feed amount storage mechanism 40 has a mounting member 41 attached to the side of the base 2, as shown in FIG.
It has a cylinder case 42 that is fixedly installed along the sliding direction of the drill unit 10 through the cylinder case 42, and a piston rod 43 that is slidably inserted into the cylinder case 42, and when the drill unit 10 moves forward. An engaging member 19 projecting laterally from the main shaft case 11 of the unit 10 engages with the rear end of the piston rod 43, thereby pushing the rod 43 into the cylinder case 42. Here, the cylinder case 42
An air supply pipe 45 is connected to the front end of the case 42 for supplying air into the case 42 to reset the piston rod 43 to the most retracted position shown in the figure. Also, a stopper shaft 4 is connected to the rear end of the piston rod 43 via a connecting member 46.
7 is inserted into the hole 41a formed in the cylinder case mounting member 41, and nuts 48, 48 are screwed onto the front end of the shaft 47.
As shown in the figure, the nuts 48, 48 are attached to the mounting member 41.
The rearward reset position of the piston rod 43 by the air is restricted at the position where the piston rod 43 comes into contact with the piston rod.

At the rear end of the piston rod 43 in the feed amount storage mechanism 40 and the engagement member 19 in the drill unit 10 located behind it, there is a detector 50 for detecting engagement between the two, and a speed sensor 50 for detecting engagement between the two. A switching position setting member 60 is provided to face each other.

The detector 50 is a limit switch attached to the engaging member 19 from the rear, as shown in an enlarged view in FIG. Tentacle 50a
Conducts when pushed in.

Further, the speed switching position setting member 60 is held by a holding member 61 fixed to the rear end of the cylindrical piston rod 43 so as to be slidable back and forth, and between the speed switching position setting member 60 and the spring receiving member 62 within the piston rod 43. It is biased rearward by a spring 63 attached to the. The rear end portion passes through the cap nut 64 screwed onto the holding member 61 and protrudes toward the detector 50 by a predetermined amount a. The amount of tightening is adjusted, and the cap nut 64 is configured to be fixed by a lock nut 65 at the adjusted position.

Here, when the drill unit 10 moves forward, the detector 50 and the speed switching position setting member 60 come into contact with each other. After being pushed into contact with the rear end surface 60a, the setting member 60 is pushed into the piston rod 43 against the spring 63 by the pressing member 51 on the detector 50 side. After that, the pressing member 51 comes into contact with the rear end surface 64a of the cap nut 64, and the piston rod 4
3 is pushed forward. In that case, the pressing member 5
In order to prevent the piston rod 43 from moving until the piston rod 1 and the cap nut 64 come into contact with each other, a friction member 70 that provides sliding resistance to the piston rod 43 is provided at the rear end of the cylinder case 42, as shown in FIG. . This friction member 70 is connected to the cylinder case 42.
The cylinder case 4 is rotated by a spring 72 installed between a cap nut 71 screwed onto the rear end.
2 and the piston rod 43 in a wedge shape.

Furthermore, this deep hole machining apparatus 1 is equipped with a feed control device 80 having a circuit configuration as shown in FIG. This control device 80 includes a hydraulic pump 81,
The hydraulic oil discharged from the pump 81 is passed through the oil passage (pipe) 25 or 26 to the forward chamber 21a or backward chamber 21 of the cylinder 21 in the feeding device 20.
a directional control valve 82 for supplying hydraulic oil to either one of the chambers and discharging the hydraulic oil in the other chamber; and the retreat chamber 21.
a speed switching valve 83 installed on the oil passage 26 between the speed switching valve 83 and the directional switching valve 82; a variable throttle valve 85 installed on the bypass path 84 that bypasses the speed switching valve 83; and the throttle valve 85. from the direction switching valve 82 to the cylinder 21 (retreat chamber 21
It has a check valve 86 that allows hydraulic oil to pass only on the b) side. Further, an on-off valve 87 is installed on the air supply path (pipe) 45 extending from an air source (not shown) to the cylinder case 42 in the feed amount storage mechanism 40 .

Next, the operation of the above embodiment will be explained.

First, when the deep hole machining apparatus 1 is started with the drill unit 10 located at the backward end as shown in FIGS. The first directional control valve 82 in the feed control device 80 in FIG.
Solenoid 82a is energized. Therefore, hydraulic oil is supplied from the pump 81 to the forward chamber 21a of the cylinder 21 in the sending device 20 through the oil passage 25, and the hydraulic oil that was filled in the retreat chamber 21b is supplied from the oil passage 26 to the speed switching valve 83 and The gas is discharged through the directional switching valve 82, and the piston 22 within the cylinder 21 is accordingly slid forward. In this case, the hydraulic oil in the retreat chamber 21b quickly passes through the speed switching valve 83, and therefore the piston 22 starts moving at high speed.

When the piston 22 starts moving forward at high speed in this way, the drill unit 10 starts moving forward at the same high speed on the base 2 via the piston rod 23 and the connecting member 24 shown in FIG. Unit 10 takes the initial stroke (4th
When the engagement member 19 of the drill unit 10 has moved forward by the dimension b) in the figure, as shown by the chain line in FIG.
The probe 50a of the detector 50 attached to the feed amount storage mechanism 40 comes into contact with the speed switching position setting member 60 provided at the rear end of the piston rod 43, and the detector 50 is electrically connected. When the detector 50 is turned on, the solenoid 83a of the speed switching valve 83 is energized in the control device 80, and the switching valve 83 is closed. Therefore, the hydraulic oil in the retreat chamber 21b of the cylinder 21 is discharged through the bypass passage 84, but since a throttle valve 85 is installed on the bypass passage 84, the discharge speed of the hydraulic oil is becomes low speed, which causes the cylinder 21
The moving speed of the piston 22 in the drill unit 10, ie, the forward speed of the drill unit 10, is switched to a low speed. From this point on, a timer (not shown) provided in the control device 80 starts counting, and the drill unit 10 is advanced at a low speed for a predetermined period of time. During this time, as shown in FIG. 6a, the tip of the drill 14 in the drill unit 10 enters the workpiece A, and the first
The next drilling operation is performed.

After that, when the set time of the above timer has elapsed,
The first solenoid 82 in the directional control valve 82
a is de-energized, and the second solenoid 82
b is excited. Therefore, the hydraulic oil discharged from the pump 81 is supplied to the retreat chamber 21b of the cylinder 21 via the check valve 86 (or the re-opened speed switching valve 83) through the oil passage 26, and the forward chamber 2
The hydraulic oil in 1a is discharged, and the piston 22 in the cylinder 21 or the drill unit 10 starts to retreat. Then, when the reverse end detection switch 30 shown in FIG. The supply of hydraulic oil to 21b is stopped, and the retreat of the drill unit 10 is stopped.
This completes the first drilling operation.

However, after the engaging member 19 engages with the piston rod 43 of the feed amount storage mechanism 40 in this operation, until the forward movement of the drill unit 10 is completed, the pressing member 5 on the engaging member 19 side
1 and the rear end surface 64a of the cap nut 64 on the piston rod 43 side are in contact with the piston rod 4.
3 is pushed into the cylinder case 42. Therefore, when the forward movement of the drill unit 10 is stopped and a hole B of a certain depth is drilled in the workpiece A as shown in FIG. Cap nut 64 at the rear end of the piston rod 43
The rear end surface 64a is located, and the drill 14, engagement member 19, etc. on the drill unit 10 side retreat, leaving the piston rod 43 or the cap nut 64 at this position.

Next, the first solenoid 82a of the directional control valve 82 is energized again by the conduction of the backward end detection switch 30, and the drill unit 10 starts moving forward, and a second drilling operation is performed. In this case, since the piston rod 43 in the feed rate storage mechanism 40 is left at a position corresponding to the bottom B' of the hole B by the first drilling operation, the drill unit 1
At the beginning of the re-advancing stroke of 0, the engaging member 19 and the piston rod 43 do not engage. Therefore, during this period, the detector 50 is not conductive, the speed switching valve 83 of the control device 80 is in an open state, and the drill unit 10 is advanced at high speed, and this high speed advancement causes the drill 14 in the unit 10 to move forward. It is inserted into hole B from the previous drilling operation. When the tip of the drill 14 reaches the bottom B' of the hole B, the engaging member 1 on the drill unit 10 side
The pressing member 51 at 9 and the rear end surface 64a of the cap nut 64 on the piston rod 43 side are engaged again, but as shown in FIG. 6b, the cap nut 6
From the rear end surface 64a of 4, the speed switching position setting member 6
0 is protruded by a predetermined amount a by the spring 63, the detector 50 is made conductive by the setting member 60 immediately before the cap nut rear end surface 64a and the pressing member 51 are re-engaged. That will happen. Therefore, the feed rate of the drill unit 10 is such that the tip of the drill 14 is at the above-mentioned dimension a of the bottom B' of the hole B.
When the hole B is inserted to the front position, the speed is changed from high speed to low speed, and in this low speed forward state, the hole B is further dug for the time set in the timer.

In this case, the speed switching position setting member 60 and the detector 50 come into contact with each other in the moving direction of the drill unit 10 and the position of the drill unit 10 is directly detected, so that the speed switching position can be determined reliably and with high precision. By loosening the lock nut 65 shown in FIG. 4 and adjusting the amount of tightening of the cap nut 64 with respect to the holding member 61, the dimension a can be finely adjusted. without shortening the high-speed feed time by making it unnecessarily large.
This makes it possible to reliably prevent the tip of the drill 14 from coming into contact with the bottom B' of the hole B at high speed. Furthermore, a friction member 70 is provided between the piston rod 43 of the feed amount storage mechanism 40 and the cylinder case 42, which applies a sliding force greater than the biasing force of the spring 63 that biases the speed switching position setting member 60 toward the detector 50. As a result, when the setting member 60 and the detector 50 come into contact, the piston rod 43 does not move and the detector 50 does not operate reliably. Since the piston rod 43 is moved after being reliably pushed into the cap nut 64, the next drilling position is memorized correctly.

In this way, by repeatedly feeding the drill unit 10 while increasing the feed rate, a gradually deeper hole is drilled.In this case, each time the drill unit 10 is fed forward, the tip of the drill 14 is Just before reaching the bottom of the previously drilled hole, the feed rate is switched from high to low. Then, when the drill has dug to a certain depth, the forward end detection switch 29 shown in FIG. , and further the switch 29
Low-speed forward feeding continues for a certain period of time from the time of conduction. However, before this time elapses, the connecting member 24 shown in FIG. 1 comes into contact with the tip 27a of the stopper shaft 27. As a result, the forward movement of the drill unit 10 is mechanically blocked at a predetermined position, and a hole of a predetermined depth can be drilled with high precision.

Incidentally, when the final drilling operation is completed and the drill unit 10 is returned to the backward position, the on-off valve 87 is opened in the control device 80 and air is supplied into the cylinder case 21 of the feed amount storage mechanism 40. . This allows the piston rod 43 in the mechanism 40 to
is reset to the original retraction end.

(Effects of the invention) As described above, according to the invention, in a deep hole machining device that drills a deep hole by repeatedly feeding the drill unit while increasing the feed rate in stages, the re-advancement of the drill unit is possible. Sometimes, the feed speed is switched from high to low just before the tip of the drill contacts the bottom of the previously drilled hole. This reduces machining time and prevents damage to the drill in this type of deep hole machining device. In particular, according to the present invention, the above-mentioned feed rate control is performed reliably and with high precision using a simple mechanical configuration, resulting in less breakdowns and easy maintenance in the event of a breakdown. An excellent deep hole drilling device will be realized.

[Brief explanation of the drawing]

The drawings show an embodiment of the deep hole drilling apparatus of the present invention, in which Fig. 1 is a vertical side view, Fig. 2 is an external side view, Fig. 3 is a plan view, and Fig. 4 is an enlarged cross-sectional plan view of the main part. FIG. 5 is a circuit diagram of the control device, and FIGS. 6a and 6b are cross-sectional plan views of essential parts showing the operating state. DESCRIPTION OF SYMBOLS 1...Deep hole processing device, 10...Drill unit, 20...Feeding device, 40...Feed amount memory mechanism, 42...Cylinder case, 43...Piston rod, 50...Detector, 60...Speed switching Position setting member, 63... Spring, 64... Adjustment mechanism (cap nut), 70... Sliding force applying mechanism (friction member), 80... Feed control device.

Claims (1)

[Scope of utility model registration request] This device drills deep holes in a workpiece by repeatedly feeding a drill unit by increasing the feed rate in stages, and is capable of moving the drill unit forward and backward and switching the forward speed between high and low speeds. A feeding device, a piston rod and a cylinder case that engage with the drill unit when the drill unit moves forward, are contracted, store the stepwise advance position of the unit as a contraction stop position, and are reset to an extended state by supplying fluid pressure. a detector provided on the drill unit side of the engagement portion between the feed amount storage mechanism and the drill unit and abuts on the feed amount storage mechanism side when engaged; and a detector on the feed amount storage mechanism side. It is provided facing the detector, and normally projects a predetermined amount toward the detector from the contact surface of the contact member on the feed amount storage mechanism side by a spring, so that the unit and the feed amount are stored when the drill unit moves forward again. A speed switching position setting member that comes into contact with the detector at a position in front of the speed switching position setting member by the amount of protrusion when re-engaging with the mechanism, an adjustment mechanism that finely adjusts the amount of protrusion of the speed switching position setting member, and the piston rod and cylinder case. A sliding force applying mechanism that applies a sliding force greater than the spring force between them and a detection signal output from a detector when the speed switching position setting member comes into contact changes the forward speed of the drill unit by the feeding device from high to high. A deep hole drilling device comprising a feed control device that switches to a low speed, continues the low speed feed operation for a certain period of time, and switches the drill unit to a backward operation after the elapse of the time.