JPS6049526B2 - Automatic drill unit control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic drill unit, and more particularly to a control device for an automatic drill unit that advances and retreats a drill using a built-in pneumatic cylinder.

More specifically, the present invention relates to improvements in a valve and its circuit for controlling the forward and backward movement of a built-in pneumatic cylinder. Conventionally, drill units that move the drill forward and backward using a built-in pneumatic cylinder can be roughly classified into two types based on their structure. One of them consists of a spindle that integrally includes rotary moving parts such as a motor and a speed reduction part, and a piston/cylinder part that is provided at a subsequent stage following this spindle.The other one is a motor, A piston rod is constituted by a spindle in which a rotary moving part such as a speed reduction part is integrally formed, and a piston is formed integrally with this spindle. A theoretical sectional view of these is shown in FIG. In the former case, as shown in FIG. 1a, both cylinder chambers 2 and 3 partitioned by the piston 1 can have substantially equal volumes.
Therefore, in order to control the propulsion speed of the piston 1, adjusting either the amount of compressed air flowing into the cylinder chamber 2 or 3 or the amount of compressed air flowing out from the cylinder chamber 2 or 3 will effectively control the propulsion speed of the piston 1. Propulsion speed can be controlled.
In other words, it is effective to adopt either the intake air restriction method or the exhaust air restriction method. However, since the piston 1 is provided separately from the spindle 4, cylinder chambers 2 and 3 with a length corresponding to the moving length of the piston 1 must be provided, so the length of the entire drill unit becomes long. It has the disadvantage of being Therefore, in recent years, as shown in Figure 1b,
Drill units in which the overall length of the drill unit is shortened by constructing the spindle 4 as a piston rod and integrally providing the piston 1 at the rear end of the spindle 4 have come into widespread use. However, since the spindle 4 is configured as a piston rod, the volume of the cylinder chamber 2'' is extremely small compared to the volume of the cylinder chamber 3''.
When an exhaust throttle is used to control the propulsion speed of the piston 1, during the forward movement of the piston 1, the cylinder chamber 2''
In order to control the forward speed of the piston 1 by adjusting the displacement of the piston 1, it is necessary to finely adjust the displacement, but even then, it is not possible to control the displacement sufficiently due to the compressibility of air. Generally, it is not used and is controlled by an air supply throttle. The present invention uses a supply air throttle to control the air supply, and by improving the structure of the pneumatic circuit and valve of the control section, the circuit has been simplified and the valve has improved performance.

The present invention will be explained below with reference to the embodiment shown in FIG.

A piston 1 is integrally attached to the rear end of the spindle 4.

2'' is a cylinder chamber formed by the inner cylinder 5, piston 1, and spindle 4, and 3'' is a cylinder chamber formed by the piston 1 and inner cylinder 5.

6 is the body of the drill unit, and 6'' is a ventilation passage provided between the body 6 and the inner cylinder 5.

7 extended backward from piston 1 - center par, 8
numeral 9 is a plate member secured to the center par 7, and an impact bolt 9 is screwed onto the plate member 8.

10 is a two-position, five-way control valve that switches the direction of movement of the piston 1; 11 is a starter valve that switches pilot air for the directional control valve 10; and 12 is the same valve. A manual return valve for switching the pilot air of the directional control valve 10, 13 is an impact bolt 9
This is an automatic return valve that switches the pilot air of the directional control valve 10 by collision with the directional control valve 10.

14 and 15 are variable throttle valves that adjust the amount of air supplied to the direction control valve 10, and 16 and 17 are direction! The pilot air throttle valves 18 and 19 of the control valve 10 are external pilots 20 and 21.
It is a check valve for.

101 to 117 are ventilation paths.

Starting valve 11. The manual return valve 12 and the automatic return valve 13 have push buttons 27, 28 and 29, and a spring 30, respectively.
, 31 and 32. Next, the operation of the present invention will be described.

FIG. 2 shows a state in which the piston 1 is at the retreating end, that is, a state in which the drill unit is stopped or just before starting operation. First, at the start of operation, compressed air is introduced from the air supply hole 24 and is sent to each valve from the air passage 101. Air passage 1
The compressed air introduced from 01 is sent to the starting valve 11 through the air passage 102, but since the starting valve 11 is always kept closed by the spring 30, it does not flow any further. Further, the compressed air sent from the ventilation path 101 to the manual return valve 12 via the ventilation path 106 does not flow any further because the manual return valve 12 is always kept closed by the spring 31. Similarly, the compressed air sent from the air passage 101 to the automatic return valve 13 via the air passage 105 is
Since the automatic return valve 13 is always kept closed by the spring 32, no further flow occurs. On the other hand, the compressed air sent from the ventilation path 101 to the directional control valve 10 via the variable throttle valve 15 provided in the middle of the ventilation path 104 does not flow any further in the illustrated state; The compressed air sent to the directional control valve 10 via the variable throttle valve 14 provided in the middle of the directional control valve 10
is introduced into the connection port 25 via the ventilation path 113,
It is sent from the air passage 6'' to the cylinder chamber 2'' and the piston 1
Press backward. At this stage, the state shown in FIG. 5 is still maintained. Next, push button 2 of starting valve 11
Press 7 to switch the starting valve 11 and open the air passages 102 and 11.
1, the compressed air introduced from the air supply port 24 acts as pilot air for the directional control valve 10 through the air passages 101, 102, 111, 112, and moves the directional control valve 10 to the right. Press and move to switch.

At this time, a part of the compressed air sent from the ventilation path 111 flows out through the throttle valve 16, but since the amount of air supplied from the ventilation path 111 is sufficiently large compared to the outflow amount,
It becomes possible to switch the direction control valve 10. on the other hand,
Air in a ventilation passage 115 provided on the opposite side to the ventilation passage 112 is discharged to the outside through a throttle valve 17. Directional control valve 1
0 has been switched, even if the starting valve 11 is returned to its original state by the spring 30, the directional control valve 10 has already been switched, and the ventilation passages 112 and 115 are both connected to the throttle valve 16 and Since the directional control valve 10 is in communication with the outside air through the directional control valve 17 and the pressure is equal, the directional control valve 10 maintains the switched state. When the directional control valve 10 is switched, the ventilation passages 104 and 114 communicate with each other, the ventilation passage 103 is closed by the directional control valve 0, and the ventilation passage 113 communicates with the outside air.
As a result, the compressed air sent from the air supply port 24 flows through the air passage 101, the variable throttle valve 15, the air passage 10, and the direction control valve 10.
, through the air passage 114 and through the connection port 26 to the cylinder chamber 3.
On the other hand, the air in the cylinder chamber 2'' is discharged from the directional control valve 10 into the outside air through the air passage 6'', the connection port 25, and the air passage 113. When the forward speed of the piston 1 is variable throttle saw valve 15
It is determined by the supply air amount set by . At the same time as the piston 1 moves forward, a motor (not shown) built in the spindle 4 rotates, and the drive shaft 4'' rotates and moves forward integrally with the spindle 4.

As the piston 1 moves forward, the center par 7, the plate member 8,
The impact bolt 9 also advances integrally, and when it advances a predetermined distance,
The collision bolt 9 collides with the push button 29 of the automatic return valve 13, switches the automatic return valve 13, connects the ventilation passages 105 and 116, and introduces pilot air into the ventilation passage 115. The control valve 10 is switched to the illustrated state. At this time, a part of the compressed air sent from the ventilation path 116 flows out from the throttle valve 17, but since the amount of air supplied from the ventilation path 116 is sufficiently large compared to the outflow amount,
It becomes possible to switch the direction control valve 10. In this way, the directional control valve 10 returns to the state shown in the figure, and the compressed air that has passed from the air supply port 24 through the air passage 101, the male throttle valve 1 air passage 103, the directional control valve 10, and the air passage 113 is transferred to the connecting port. 25, is introduced into the cylinder chamber 2'' through the ventilation passage 6, and presses the piston 1 backward.On the other hand, the air in the cylinder chamber 3'' passes through the connection port 26, the ventilation passage 114, the directional control valve 10, and enters the outside air. released. As the piston 1 retreats, the center par 7, plate member 8, and impact bolt 9 also retreat,
The collision between the impact bolt 9 and the push button 29 of the automatic return valve 13 is released, and the automatic return valve 13 returns to the illustrated state by the action of the spring 32. In this case, as in the case of the starter valve 11 described above, after the automatic return valve 13 returns, the air passage 1
12 and 115 are in communication with the outside air through throttle valves 16 and 17, respectively, and the pressures are equal, so that the directional control valve 10 maintains the state shown. The piston 1 is pushed backward and continues to move backward until it finally reaches the state shown in the figure and stops. Simultaneously with the stop, the motor (not shown) built into the spindle 4 stops, completing one cycle of operation. To start the next operation, the push button 27 of the starter valve 11 is pressed again, and the above operations are performed in sequence. Here, instead of operating the starting valve 11, air is sent into the air passage 112 by supplying compressed air from a solenoid valve (not shown) or other automatic valve connected to the external pilot 20, and the starting valve 11 is It can achieve the same effect as if it were activated.

Also, instead of operating the automatic return valve 13, the manual return valve 12
It is clear from the circuit configuration that by operating the automatic return valve 13, the same effect as operating the automatic return valve 13 can be achieved.
This manual return valve 12 is effectively used when adjusting the stroke of the drill unit or for emergency retreat. Furthermore, an automatic return valve 13 and a manual return valve 12
Instead, air was sent into the ventilation passage 115 by sending compressed air from a solenoid valve (not shown) or other automatic valve connected to the external pilot controller 21, and both return valves 12 and 13 were actuated. It can achieve the same effect as . Next, the configuration of the directional control valve 10 will be explained.

What is shown in FIG. 3 is a sectional view of a conventionally frequently used directional control valve, which will be described below in connection with the embodiment of the present invention shown in FIG. This directional control valve has a fitting hole 5 formed in a valve body 49.
1 and the ventilation passage 112 , a passage 43 communicating with the ventilation passage 103 ), a passage 45 communicating with the ventilation passage 104 , a passage 46 communicating with the ventilation passage 115 , a ventilation passage 113 A through hole 47 that communicates with the air passage 114, a through hole 48 that communicates with the air passage 114, and a through hole 44 that communicates with the outside air are bored.
An O-ring 52 is fitted to the valve body 49 as a sealing member 7 between the spool 41 and the valve body 49. In the directional control valve having such a configuration, when pilot air is introduced from the through hole 42 through the air passage 112, the state shown in FIG. 48 communicate with each other and can move the piston 1 forward. That is, the push button 27 of the starting valve 11 is pressed. Conversely, when pilot air is introduced from the through hole 46 through the air passage 115, the state shown in FIG. can be set back. That is, the push button 28 or 29 of the return valve 12 or 13 is pressed. However, the O-ring 5 is used as a sealing member.
2, an O-ring 52 is used to achieve the seal.
Usually, the C-ring 52 acts as a resistance against the movement of the spool 41 and causes the spool 41 to malfunction. Furthermore, if you try to start it after it has been left without operating for a long time, as a phenomenon peculiar to the 0 ring, the 0 ring 5
2 is stuck to the spool 41, and the spool 41 is not operated by pilot air, which tends to cause the spool 41 to malfunction. Therefore, in the present invention, as shown in the embodiment of FIG.
Passages 43 and 45 communicating with the air supply port of the directional control valve 10 are arranged on both sides, and a through hole 44 communicating with the outside air is connected to the passage 43.
and 45, a lip packing 50 is attached to the spool 41, which acts only in one predetermined direction as a sealing member at each sealing part due to the pressure of compressed air. be. By installing the lip packing 50 in this way, a seal can be achieved, and the sliding resistance of the spool 41 is extremely small.Furthermore, even if the spool is restarted after being left unused for a long time, no sticking phenomenon will occur, and the spool 41 will not stick. In addition, due to the low sliding resistance, it is possible to operate reliably even when the pilot air pressure is low, and as a result, the directional control valve can be made smaller. It is something. The third effect is that when pilot air is introduced from the through hole 42 in FIG. 4, the state shown in FIG. Then, the second
When the piston 1 in the figure is moved forward and pyrotechnic air is introduced from the through hole 46, the piston 1 shown in FIG.
In this state, the through holes 43 and 47, and the through holes 44 and 4
8 communicate with each other to retract the piston 1 in FIG. As described above, the operation is no different from that of the conventional structure, and the conventional structure used six O-rings 52 as shown in FIG. 3, but in the present invention, four lip packings 50 are used. By attaching them individually and constructing them as shown in FIG. 4, the purpose was effectively achieved. On the other hand, if we look at the circuit configuration, as shown in Figure 5a, a throttle valve is generally provided between the directional control valve 10 and the cylinder as shown in Fig. 5a. In order to do this, it is necessary to install a check valve in parallel with the throttle valve, which makes the circuit more complicated and increases the number of parts.

In the present invention, by employing the circuit configuration shown in FIG. 5b, it is possible to simplify the circuit and reduce the number of parts. As detailed above, the present invention has a simpler circuit compared to conventional devices, can reduce the number of component parts and reduce processing costs, and can further improve the sealing part of the directional control valve. This makes it possible to achieve stable performance, longer life, and smaller size.

[Brief explanation of drawings]

1A and 1B are vertical cross-sectional views showing the principle of construction of a drill unit, FIG. 2 is a circuit diagram of an embodiment of the control device according to the present invention, and FIGS. 3A and 3B are diagrams showing a conventional directional control valve. FIGS. 4A and 4B are vertical sectional views showing an embodiment of the directional control valve according to the present invention, FIG. 5A is a circuit diagram of a conventional directional control valve, and FIG. FIG. 3 is a circuit configuration diagram of a control valve.

Claims (1)

[Scope of Claims] 1. In an automatic drill unit that integrally includes a drive shaft, a prime mover, a propulsion device, and a control device, and is equipped with a propulsion cylinder using compressed air, 2. A spool system for controlling the movement direction of the propulsion cylinder. Two sides of the five-way directional control valve are connected to the cylinder chamber of the propulsion cylinder, the other two sides are connected to the air supply port, and the remaining one is connected to the exhaust port, and the pilot air for switching the directional control valve is connected to the cylinder chamber of the propulsion cylinder. One side is branched and one side is connected to the air supply port through a starting valve consisting of a two-position two-way valve, the other side is connected to the outside through a check valve, and the other side is connected to the throttle valve. The remaining one is connected to the air supply port via an automatic return valve consisting of a two-position two-way valve, and the two sides communicating with the air supply port of the directional control valve are arranged on both sides. A control device for an automatic drill unit, wherein one side communicating with the exhaust port is arranged between the two sides. 2. The automatic drill unit control device according to claim 1, wherein a lip packing is fitted to the spool of the directional control valve.