JPS6254602B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a feeding mechanism for a drill for drilling holes of extremely small diameter used in special-purpose machines for drilling nozzle holes in injection nozzles.

Conventionally, a dedicated machine for drilling injection holes (diameter 0.1 to 1 mm) in the injection nozzle of a fuel injection pump was
The drilling drill was fed by hand using a rack and pinion, or by using a feed screw to make the cut.

Since the equipment employs a manual feeding mechanism using a rack and pinion, it is impossible for each person to handle more than one unit, and therefore drilling the nozzle hole is a task that requires a high labor cost. . Further, the latter type using a feed screw had a complicated structure and was expensive.

In view of the above-mentioned reasons, this invention has relatively simplified the structure of a micro-diameter nozzle drilling machine, allows automatic step feed, and allows easy detection of damage to the drill. In order to realize mechanical feeding of extremely small diameter drills, there is a spring that acts in the feeding direction of the drill, and a spring that opposes the spring and controls the idle feeding speed of the drill. A cylinder having a limiting piston rod, a position detection means provided at the cutting start position and cutting completion position of the drill, a cutting time timer for setting the cutting time, and a cutting time timer set to a time shorter than the cutting time. It consists of a breakage detection timer and a cutting defect detection timer set to a time longer than the cutting time, the spring force of the spring is set slightly larger than the cutting resistance force of the workpiece by the drill, and the cylinder The piston rod is configured to reverse the protruding and retracting direction of the piston rod based on a signal from the position detecting means of the cutting start position of the drill and a signal from the cutting timer or the position detecting means of the cutting completion position, and to prevent the damage. When the timer receives a signal from the position detection means of the cutting completion position within the set time, or when the poor cutting quality detection timer does not receive a signal from the position detection means of the cutting completion position within the set time, Each timer is configured to display a signal indicating this fact, and the simple configuration can prevent damage to the drill and reduce man-hours.

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, a schematic configuration diagram of an embodiment of the present invention is shown, in which a drill 2 for drilling an injection hole of an injection nozzle 1 is fixedly attached to a spindle 3 and provided on the end side of the spindle 3. pulley 4, belt 5,
Rotational force is transmitted from the motor 7 via the pulley 6, and the drill 2 is rotated.

The spindle 3 is provided with a lever 8 which is rotatable and engages in the axial direction, and a force of a spring 9 is applied to the lever 8. Therefore, the drill 2 is pressed toward the injection nozzle 1 by the force of the spring 9.

Limit switches 13 and 14 are provided at the cutting start position and the cutting completion device in the direction of movement of the lever 8 to detect movement of the drill 2.

A cylinder 10 is provided opposite the spring 9, and the tip of the piston rod 11 of the cylinder 10 contacts the lever 8 at the cutting start position. This cylinder 10 is moved by switching the switching valve 12, and when the switching valve 12 is switched into position or position,
Pressure oil flows into the cylinder head side or the piston rod side, causing the piston rod 11 to expand and contract. At this time, since a throttle 15 is provided in the hydraulic circuit connected to the cylinder head side, the piston rod 11
The moving speed of is controlled by this aperture.

In the above configuration, when the nozzle hole drilling machine is not in a cutting state and is not in use, it is in the retracted position shown by the two-dot chain line in FIG. When the cutting progresses to the point, the piston rod 11 of the cylinder 10 temporarily stops, but the limit switch 13 for detecting the start of cutting is turned on, so the switching valve 12 is switched to the position side, and the piston rod 11 of the cylinder 10 is moved to the throttle 15. At a predetermined retraction speed limited by Then, the drill 2 feeds the cutting at a cutting speed that is balanced with the cutting resistance and the pressing force of the spring 9.

In this FIG. 2, the step feed of the drill is illustrated, and the switching valve 12 is switched by the signals of the cutting time of 0.5 sec and the return time of the drill 2 of 0.3 sec, which are set by the cutting time timer, and the signals of the limit switches 13 and 14. Cutting is performed by reversing the feed direction of the drill and performing three step feeds.

The movement of the tip of drill 2 is shown by a solid line, and the angle θ
₁ indicates the cutting speed of the cylinder 10 for controlling the cutting depth, and the characteristic line indicated by the angle θ ₂ is the speed at which the cutting resistance is balanced by the pressing force of the spring in the cutting state. When the cutting time of 0.5 seconds set by the cutting time timer ends, the switching valve 12
is switched, the piston rod 11 moves forward, and the lever 8 moves to the limit switch 13 at the cutting start position.
Return drill 2 to the position where it turns on.

When the cutting is completed during the third step feed, the drill 2 runs idle and strokes to the maximum, and the limit switch 14 for detecting the completion of cutting is turned on. As a result, the completion of cutting is detected, and the drill 2
is returned by the piston rod 11 of the cylinder 10 moving forward to the cutting start position.

Breakage detection is when drill 2 is broken and there is no drill.
Or, in the case of a mistake in mounting the workpiece (injection nozzle 1), the limit switch 14 is turned on within the damage detection timer set time of 0.3 seconds, which is shorter than the cutting time of 0.5 seconds set by the cutting time timer, after cutting starts. This can be detected by
The limit switch 14 is turned on within the set time of the damage detection timer of 0.3 sec. In this way, when a signal from the limit switch 14 is received within the set time of the damage detection timer, this indicates a problem such as damage to the drill, and is displayed on an external display to inform the operator.

In addition, if the limit switch 14 is not turned on and the signal from the limit switch 14 is not received within a time period longer than the cutting time defect detection timer set time of approximately 4 seconds, that is, the time of three step feeds, the sharpness of the drill 2 is detected. This is a defect and is displayed on the external display device. In this case, replace drill 2.

In this embodiment, limit switch 1
3, 14 and the switching valve 12, and when the limit switch 14 is turned on within the breakage detection timer time, the electric circuit and cutting defect detection, such as displaying a signal of no drill or no workpiece, is performed. The electric circuit that oscillates an electric signal indicating poor cutting when the limit switch 14 is not turned on within the timer set time is a known circuit known to those skilled in the art, and is not described in this embodiment.

As described above, this invention includes a cylinder having a spring acting in the feed direction of the drill, a piston rod opposing the spring and limiting the idle feed speed of the drill, and a cylinder provided at the cutting start position and the cutting completion position of the drill. a limit switch, a cutting time timer for setting the cutting time, and a breakage detection timer set to a time shorter than the cutting time, and the cutting feed of the drill is slower than the idle feed speed limited by the piston rod. The cutting speed is balanced by the spring force and the cutting resistance of the workpiece, and the feed direction of the drill is reversed based on the limit switch signal at the cutting start position and the cutting time timer or the limit switch signal at the cutting completion position. In addition, when a signal from the limit switch at the cutting completion position is received within the time set by the damage detection timer, and when a signal from the limit switch at the cutting completion position is not received within the time set by the poor sharpness detection timer, the respective states Since the drill feed mechanism is designed to display , the mechanism is extremely simplified compared to conventional ones, and the idle feed speed is such that the drill will not break due to impact when it comes into contact with the workpiece, and the cutting speed can be increased. The faster speed eliminates damage to the drill, shortens the feed time, and cuts in a balance between the sharpness of the drill and the pressing force of the spring, which prevents excessive force from being applied to the drill and reduces damage to the drill. The difference between the cutting quality of the drill and the amount of cutting is adaptable, as if the cutting quality is good, it will advance quickly, and if it is bad, it will be slow. This will make it easier. In particular, when it comes to detecting damage to drills with a small diameter of 0.2 to 1 mm, conventional methods such as abnormal vibration detection, cutting torque detection, and phototube detection are uncertain, but the provision of a damage detection timer has made this possible. This is an extremely effective invention.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of the present invention, and FIG. 2 is an explanatory diagram illustrating the cutting state of the present invention. 1...Injection nozzle, 2...Drill, 8...Lever, 9...Spring, 10...Cylinder, 11...Piston rod, 12...Switching valve, 13...Limit switch, 14...Limit switch.

Claims (1)

[Claims] 1. A cylinder having a spring acting in the feed direction of the drill, a piston rod opposing the spring and limiting the idle feed speed of the drill, and position detection means provided at the cutting start position and the cutting completion position of the drill; It consists of a cutting time timer that sets the cutting time, a breakage detection timer that is set to a shorter time than the cutting time, and a poor cutting timer that is set to a longer time than the cutting time. The spring force of is set slightly larger than the cutting resistance force of the workpiece by the drill, and the cylinder is
The direction of protrusion and retraction of the piston rod is reversed based on the signal from the position detection means of the cutting start position of the drill and the signal from the cutting timer or the position detection means of the cutting completion position, and the breakage timer is activated. When the signal from the position detection means of the cutting completion position is received within the set time, or when the poor cutting quality detection timer does not receive the signal from the position detection means of the cutting completion position within the set time, each A drill feeding mechanism for a dedicated nozzle hole drilling machine, characterized in that a timer displays a signal indicating this fact.