JPH1164130A - Welding pressure gauge for spot welding gun and method for using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a welding pressure gauge for a spot welding gun which can safety measure the pressuring force without requiring a deceleration circuit in the pressure driving circuit of the spot welding gun. SOLUTION: Electricity is applied to a work while the work is pinched between both electrode tips 2, 4 by pneumatically driving one electrode tip 4 by air cylinders 10, 10a toward the other electrode tip 2. The upper parts of the pair of the air cylinders 10, 10a kept from each other are connected by a cylinder connecting plate 11 as to position the cylinders in both sides of the electrode tip 2 and at the same time the tip end parts of cylinder rods 13, 13a in both sides are connected with a rod connecting plate 15. Further, a pressure sensor 12 is positioned in the middle position of the cylinder connecting plate 11 and projected part 15a with a shape to be matched with the tip end part of the electrode tip 4 is formed in the down face of the rod connecting plate 15 at the position corresponding to the pressure sensor 12. Furthermore, gas suction and discharge ports 17 of the inlet side cylinder chambers of the air cylinders 10, 10a are opened to the air manually operable flow rate control valve 18, 18a are installed in gas suction and discharge parts 17a in the outlet side cylinder chambers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for energizing a workpiece by sandwiching the workpiece between the two electrode tips by driving the other electrode tip toward the one electrode tip with an air cylinder. The present invention relates to a pressure gauge for a spot welding gun for measuring pressure.

[0002]

2. Description of the Related Art As shown in FIG. 5, in a spot welding gun provided with an electrode tip 2 facing an arm 1 and an electrode tip 4 which is driven to be pressed by an air cylinder 3, between the two electrode tips 2,4. In order to measure the pressing force when energizing the workpiece while holding it, the pressure cylinder 6 is set on the fixed-side electrode tip 2 and the air cylinder 3 is operated.

[0003]

Therefore, if the pressure gauge 6 is set out of position, it may be damaged, and there is a problem in safety. In order to reduce the gun pressurizing speed, an air cylinder is provided with an air control circuit for reducing the speed.

In view of the foregoing, the present invention provides a pressure gauge for spot welding guns that can safely measure without preparing a deceleration circuit in the pressure driving circuit of the spot welding gun. Aim.

[0005]

According to the present invention, in order to achieve this object, a work is performed by pressing one electrode tip toward an electrode tip by an air cylinder. In a pressure gauge for a spot welding gun for measuring the pressure when energizing while sandwiching between the two electrode tips, a pair of air cylinders spaced apart from each other so as to be located on both sides of one electrode tip. The upper portion is connected by a cylinder connecting plate, the tip ends of the cylinder rods on both sides of the air cylinder are connected by a rod connecting plate, and a pressure sensor is disposed at an intermediate position with respect to the air cylinders on both sides of the cylinder connecting plate. Forming a projection corresponding to the tip of the other electrode tip on the lower surface of the connection plate corresponding to the pressure sensor The supply and exhaust port of the inlet-side cylinder chamber of the air cylinder causes release to the atmosphere, characterized in that a manually operated flow control valve in the air supply and exhaust port of the outlet-side cylinder chamber.

[0006] A pressure sensor is mounted on one electrode chip while one electrode chip is sandwiched between air cylinders on both sides. The cylinder connecting plate is raised and brought into contact with the other electrode tip so that the protrusion is coaxial. The flow control valve is pressurized while being throttled, and the other electrode tip is gradually reduced by a manual operation by gradually reducing the throttle amount of the flow control valves 18 and 18a, and is lowered at a low speed. Abut.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A pressure gauge for a spot welding gun according to an embodiment of the present invention will be described with reference to FIGS. The pressure gauge connects a pair of air cylinders 10 and 10a separated from each other with a cylinder connection plate 11 so as to be located on both sides of the electrode tip 2 on the fixed side of the spot welding gun illustrated in FIG. The distal ends of the cylinder rods 13 and 13a are connected by a rod connecting plate 15, and a pressure sensor 12 is disposed at an intermediate position with respect to the air cylinders 10 and 10a on both sides of the cylinder connecting plate 11, and the rod connecting plate 1
5 is provided with a spherical projection 15a having a shape corresponding to the tip of the movable-side electrode tip 4 on the lower surface at the intermediate position in the vertical direction.

A cylinder connecting plate 11 is mounted on the upper surfaces of the air cylinders 10 and 10a, and guide holes 1 for inserting cylinder rods 13 and 13a at both ends thereof.
1a is formed. The pressure sensing element 12a at the center of the pressure sensor 12 occupies the middle position in the vertical direction of the cylinder connecting plate 11, and the protrusion 15a is positioned so as to occupy a position in contact with the center of the pressure sensing element 12a. The chips 2, 4, the pressure-sensitive element 12a, and the protrusion 15a are aligned in the coaxial direction.

On the lower surface of the cylinder connecting plate 11, a positioning gauge 16 for positioning the electrode tip 2 at a position facing the pressure-sensitive element 12a is provided. Similarly,
The upper surface of the rod connecting plate 15 is also provided with a spherical projection 15.
There is provided a positioning gauge 16a for positioning a a coaxially with the electrode tip 4. These positioning gauges are provided with inlets for the electrode chips 2 and 4 to enter in front, respectively, and the rear portion is formed in a corresponding semicircle surrounding these electrode chips with a slight gap.

The air supply / exhaust ports 17 of the inlet side cylinder chambers of both air cylinders 10, 10a are open to the atmosphere.
The air supply / exhaust port 17a of the outlet side cylinder chamber is provided with a manually operated completely closable flow control valve 18, 18a, respectively.

The operation of the pressure gauge for a spot welding gun thus configured will be described with reference to FIG. The force gauge is inserted so as to sandwich the fixed electrode tip 2 below the spot welding gun (FIG. 4A). At this time, the electrode tip 2 is made to enter the positioning gauge 16, is set at a reference position having a uniform gap around it, and the back side of the pressure-sensitive element 12 a is placed on the electrode tip 2. In this state, the cylinder connecting plate 11 is in a state where both air cylinders 10, 10a are floating. Next, the cylinder connecting plate 11 is raised with the flow control valve 18 largely released, and the positioning gauge 16a is set so as to occupy a reference position with respect to the electrode tip 4 (FIG. B). As a result, the pressure-sensitive element 12a is driven by the pressure driving of the electrode tip 4 so that the protrusion 15a is formed.
Is set in a state where a load is applied at the central portion via the.

With the flow control valve 18 closed, the electrode tip 4
Is pressurized to gradually reduce the throttle amount of the flow control valves 18 and 18a individually by manual operation so as to balance the air cylinders 10 and 10a on both sides, thereby lowering the electrode tip 4 at a low speed to obtain a spherical projection. The part 15a is connected to the pressure sensitive element 12a.
, And finally the pressure is measured by the detection signal of the pressure sensor 12 in a state where the flow control valves 18 and 18a are completely opened (C in the figure).

When both cylinder rods are operated so that the operating speeds are the same, it is conceivable to provide a single flow control valve for both air cylinders.

[0014]

According to the first and third aspects of the present invention, there is provided a pressure gauge for a spot welding gun capable of measuring a pressure force safely and at low cost without providing a dedicated deceleration air circuit in the spot welding gun. Is achieved. According to the second aspect of the present invention, the provision of the positioning gauge makes it possible to easily and accurately set the pressure sensor on the electrode chip.

[Brief description of the drawings]

FIG. 1 is a front view of a pressure gauge for a spot welding gun according to an embodiment of the present invention.

FIG. 2 is a plan view of the pressure gauge.

FIG. 3 is a plan view of a cylinder connecting plate portion of the pressure gauge.

FIG. 4 is a side view illustrating the operation of the pressure gauge.

FIG. 5 is a diagram illustrating a measurement state of a conventional pressure gauge for a spot welding gun.

[Explanation of symbols]

 2, 4 Electrode tip 10, 10a Air cylinder 11 Cylinder connection plate 12 Pressure sensor 13, 13a Cylinder rod 15 Rod connection plate 17 Supply / exhaust port 18, 18a Flow control valve

Claims (3)

[Claims] 1. An apparatus for measuring a pressing force when a workpiece is sandwiched between two electrode tips and energized by driving one electrode tip toward the other electrode tip by an air cylinder. In a pressure gauge for a spot welding gun, an upper portion of a pair of air cylinders separated from each other so as to be located on both sides of one electrode tip is connected by a cylinder connecting plate, and a tip of a cylinder rod on both sides of the air cylinder. The parts are connected by a rod connecting plate, and a pressure sensor is arranged at an intermediate position with respect to the air cylinder on both sides of the cylinder connecting plate,
A projecting portion having a shape corresponding to the tip of the other electrode tip is formed at a portion corresponding to the pressure sensor on the lower surface of the rod connection plate, and a supply / exhaust port of an inlet side cylinder chamber of the air cylinder is opened to the atmosphere. A pressure gauge for a spot welding gun, wherein a manually operated flow control valve is provided at a supply / exhaust port of an outlet side cylinder chamber. 2. A positioning gauge for positioning one electrode tip at a position corresponding to the pressure sensor on the lower surface of the cylinder connecting plate, and the other at a position corresponding to the protrusion on the upper surface of the rod connecting plate. The pressure gauge for a spot welding gun according to claim 1, further comprising a positioning gauge for positioning the electrode tip. 3. The pressure gauge for a spot welding gun according to claim 1, wherein a cylinder connecting plate is placed on one of the electrode tips so as to face the pressure sensor, and the cylinder connecting plate is raised to a projecting portion thereof. The other electrode tip is opposed, the other electrode tip is pressurized and driven with the flow control valve squeezed, and the throttle amount of the flow control valve is gradually reduced by manual operation so that the protrusion contacts the pressure sensor. A method for using a pressure gauge for a spot welding gun, wherein the pressure gauge is in contact with the spot welding gun.