CN114279629A - Hydraulic torque wrench calibrating device - Google Patents

Abstract

The invention discloses a hydraulic torque wrench verification device. An input end of a sensor is provided with a bolt simulation device, comprising a square head bolt, two disc springs and a hexagonal nut; In contrast, the center of the disc spring is provided with a round hole, which is sleeved on the square head bolt through the round hole; the hexagonal nut is threadedly connected with the square head bolt; There is an extrudable space between the disc springs; the end of the square head bolt protrudes from the hexagonal nut. The beneficial effect of the present invention is that the bolt simulating device is provided, the movement of the bolt can be well simulated during the detection process, thereby ensuring that the detection of the hydraulic torque wrench is closer to the actual torque value. A stepped block assembly is also provided to provide a reliable reaction arm for different sizes of wrench bars.

Description

Hydraulic torque wrench verification device

technical field

The invention belongs to torque wrench testing equipment, in particular to a hydraulic torque wrench testing device.

Background technique

In order to complete the detection of the output torque accuracy of the hydraulic torque wrench, the technology and products of the hydraulic torque wrench calibrator have now appeared. For example, the patent number CN201289421Y applied by our company is called the hydraulic torque wrench calibrator. The existing hydraulic torque wrench calibrator is mainly composed of a digital display instrument, a casing, a torque sensor, an adapter, a reaction arm block and a bottom plate. Although the current detector can detect, it cannot obtain the real torque value of the hydraulic torque wrench due to the shortcomings of the structure. The specific reason is that the torque sensor used in the detector is a static torque sensor, and the measuring elastic body of the static torque sensor cannot participate in the relative motion. When testing the hydraulic torque wrench, the static torque sensor is fixed on the housing, and the square tenon or hexagonal port of the hydraulic torque wrench as the output end is fixed and cannot be rotated after being matched with the interface of the static sensor. In this way, when the hydraulic torque wrench is loaded and detected, the position of the piston in the hydraulic torque wrench is also fixed during the loading process. When the hydraulic torque wrench loads the bolt, the piston needs to perform telescopic activities in the oil cylinder, and the piston drives the ratchet drive mechanism to output the torque. In such a mechanism, under the same pressure, the magnitude of the torque output value will be affected by the position of the piston. Within the piston stroke range, the torque output variation range can reach ±10%~±15%. Usually, the torque output by the piston at the starting position is the smallest; when the piston is near the middle of the stroke, the output torque is the largest.

On the production line, there are often cases where the bolts are broken and the test results of the hydraulic torque wrench are qualified. The fundamental reason is that, due to the defects of the existing testing equipment, when the hydraulic torque wrench is pressurized and tested, the piston position is fixed, and it is easy to make the piston at the initial position, so that the detected output torque value is the smallest. And users often use this torque value as the output value of the hydraulic torque wrench. In the actual use process, because the bolt or nut loaded by the hydraulic torque wrench can be rotated, the torque value gradually increases until the maximum value is reached as the piston extends during the loading process, which will easily exceed the allowable torque of the bolt. value and cause damage to the bolt.

SUMMARY OF THE INVENTION

In view of this, the present invention provides a hydraulic torque wrench verification device, by simulating the real loading process of the hydraulic torque wrench on the bolt, the detection result closest to the actual torque value is obtained, and the inaccurate results caused by the structural defects of the original detection equipment are solved. The problem.

The technical scheme adopted in the present invention is: a hydraulic torque wrench verification device, comprising a casing, a sensor installed in the casing and a reaction arm assembly installed on the casing, the output end of the sensor is connected to an external digital display through a cable It is characterized in that: a bolt simulation device is provided at the input end of the sensor, and the bolt simulation device includes a square head bolt, two disc springs and a hexagonal nut; There is a round hole in the center of the disc spring, which is sleeved on the square head bolt through the round hole; the hexagonal nut is threadedly connected with the square head bolt; the disc spring is squeezed by the square head bolt and the hexagonal nut, and the two discs are There is an extrudable space between the springs; the end of the square head bolt protrudes from the hexagonal nut.

Further, the height at which the end of the square head bolt protrudes from the hexagonal nut is L, and a pitch of the thread of the square head bolt is P, L≤P.

Further, the height of the compression space of the disc spring is h, and h≧P.

Further, the reaction arm assembly is a stepped block assembly, including a fixed seat and a stepped block, the fixed seat includes a cylinder fixed on the upper end of the square body, and the bottom end of the square body is fixedly connected with the casing; The through hole in the center of the stepped stopper is sleeved on the outer cylinder of the fixed seat to form a clearance fit; the outer contour of the stepped stopper includes a section of circular arc and two or more steps, and the circular arc is concentric with the through hole and is in phase with the through hole. The distance between the plane adjacent to the step and the center of the through hole is gradually distributed, and the connecting line between the step plane and the center of the through hole is perpendicular to the step plane.

Further, the lengths of the stepped planes are the same.

Further, the stepped block assembly is also provided with an adjustment pad. The adjusting pad is an L-shaped plate, and the width of the adjusting pad is adapted to the length of the stepped plane.

Further, the hexagonal nut is sleeved with a sleeve, one end of the sleeve is a hexagonal opening, and the other end is a square opening.

The beneficial effect of the present invention is that the bolt simulating device is provided, the movement of the bolt can be well simulated during the detection process, thereby ensuring that the detection of the hydraulic torque wrench is closer to the actual torque value. A stepped block assembly is also provided to provide a reliable reaction arm for different sizes of wrench bars.

Description of drawings

Figure 1 is a schematic diagram of the overall structure of the present invention.

FIG. 2 is a schematic structural diagram of a bolt simulator in the present invention.

Figure 3 is a schematic structural diagram of a square head bolt.

Figure 4 is an assembly view of the stepped stopper assembly.

FIG. 5 is a schematic view of the structure of the fixed seat.

FIG. 6 is a schematic structural diagram of a stepped stopper.

FIG. 7 is a schematic view of the structure of the adjusting pad.

FIG. 8 is a schematic diagram of the detection of the driving hydraulic torque wrench according to the present invention.

FIG. 9 is a schematic diagram of the detection of the hollow hydraulic torque wrench according to the present invention.

In the picture: 1. Digital display, 2. Housing, 3. Sensor, 4. Bolt simulation device, 4-1, Hex nut, 4-2, Disc spring, 4-3, Square head bolt, 4-4 , Block, 5, Sleeve, 6, Ladder block assembly, 6-1, Fixed seat, 6-2, Ladder block, 6-3, Adjustment pad, 7, Cable, 8, Driven hydraulic Torque wrench, 9. Hollow hydraulic torque wrench.

Detailed ways

In order to make those skilled in the art better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

As shown in FIG. 1 , the present invention includes a sensor 3 installed in the housing 2 and a reaction arm assembly installed on the housing 2 . The output end of the sensor 3 is connected to an external digital display 1 through a cable 7 . This structure is a common structure of a verification device, and will not be repeated here.

The key point of the present invention is to add a bolt simulation device 4 to the input end of the sensor 3, so as to simulate the real state of the hydraulic torque wrench when the bolt is tightened. In such a testing environment, a more realistic torque value can be obtained by testing the hydraulic torque wrench. The specific structure of the bolt simulation device 4 is as follows:

As shown in FIG. 2 , the bolt simulation device 4 includes a square head bolt 4-3, two disc springs 4-2 and a hexagonal nut 4-1. As shown in FIG. 3 , the square head bolt 4-3 includes a square head and a section of bolt, and a stop 4-4 is provided between the square head and the bolt. The shape of the square head matches the shape of the input end of the sensor 3 . The square head can be plugged into the input end of the sensor 3 . The center of the two disc springs 4-2 is provided with a circular hole. The flared openings of the two disc springs 4-2 abut on the bolt through the round hole. The diameter of the upper stop 4-4 of the square head bolt 4-3 is larger than the diameter of the circular hole of the disc spring 4-2. The hexagonal nut 4-1 is screwed on the bolt extending out of the circular hole of the disc spring 4-2. The lower end of the disc spring 4-2 is abutted against the stop 4-4, and the upper end of the disc spring 4-2 is abutted against the hexagonal nut 4-1. Tighten the hexagonal nut 4-1 to squeeze the two disc springs 4-2 to the stop 4-4.

It should be noted that the height L of the end of the bolt beyond the hexagonal nut 4-1 should be less than or equal to a pitch P of the thread on the bolt. After the bolt simulation device 4 bears the test torque load, the total compression amount h of the butterfly spring must satisfy the condition of h≥P. This is because: limited by the size of the ratchet mechanism in the hydraulic torque wrench and the stroke of the piston, the maximum angle that the piston can push the nut to rotate each time does not exceed 40°. For hydraulic torque wrenches, detecting an accurate torque value requires at least 3 reciprocating movements of the piston until the nut can no longer turn. That is, the nut needs to be turned 120°. Corresponding to the bolt simulator of the present invention, one thread pitch P is equivalent to a 360° rotation of the hexagonal nut 4-1. When the hydraulic torque wrench is loaded with torque more than 3 times, the minimum angle φ that the hexagon nut 4-1 should rotate is 120°. Therefore, the compression amount of the disc spring 4-2 should satisfy h≥P.

As shown in FIG. 8 , when testing the driven hydraulic torque wrench 8, a sleeve 5 needs to be fitted on the hexagonal nut 4-1 of the bolt simulation device 4. One end of the sleeve 5 is a square port and the other end is a hexagonal port. The wrench head of the driving hydraulic torque wrench is connected with the square port of the sleeve 5 , and the hexagonal port of the sleeve 5 is connected with the hexagonal nut 4 - 1 on the bolt simulation device 4 .

As shown in FIG. 9 , when testing the hollow hydraulic torque wrench 9 , there is no need to increase the sleeve 5 , and it is only necessary to directly fit the wrench head on the hexagonal nut 4 - 1 of the bolt simulation device 4 .

As shown in FIGS. 4 to 6 , in order to match hydraulic torque wrenches with different arm lengths, the original reaction arm block on the housing 2 is improved into a stepped block assembly 6 . The stepped block assembly 6 includes a fixed seat 6-1 and a stepped block 6-2. The fixed seat 6-1 is fixedly connected with the housing 2, and the stepped block 6-2 is sleeved on the fixed seat 6-1. The specific structure is as follows:

As shown in Figure 5, the fixed seat 6-1 consists of a cylinder and a square. The bottom end of the square is fixedly connected to the housing 2 through locking bolts, and the cylinder is fixed on the top of the square. The central axis of the cylinder and the square coincide.

As shown in FIG. 6, the stepped stopper 6-2 is a cylindrical member. The center of the stepped stopper 6-2 is provided with a through hole, and the diameter of the through hole is adapted to the outer diameter of the cylinder of the fixed seat 6-1. The stepped block 6-2 is sleeved on the cylinder of the fixed seat 6-1 through the through hole to form a clearance fit. The outer contour of the stepped stopper 6-2 includes an arc and two or more steps. As an example, the number of steps may be set to five. The arc is concentric with the through hole. The distances between the planes of the adjacent steps and the center of the through holes are distributed in an equal and increasing manner. The line connecting the stepped plane and the center of the through hole is perpendicular to the stepped plane. The length K of each step plane is the same.

As shown in FIG. 7 , the stepped block assembly 6 is further provided with an adjustment pad 6-3. The adjusting spacer 6-3 is an L-shaped plate. Adjust the width of the spacer 6-3 to match the length K of the stepped plane. When in use, just hang the adjusting pad 6-3 on the stepped surface of the stepped block 6-2. The replacement position can be removed at any time.

When using the stepped block assembly 6, fit the stepped block onto the cylinder of the fixed seat 6-1. As shown in Figures 8 and 9, the wrench head of the hydraulic torque wrench is connected to the bolt simulation device 4, and the wrench rod is abutted against one of the stepped planes of the stepped block 6-2, so that the stepped plane is parallel to the force-bearing surface of the wrench rod , which can provide a reliable reaction force for the hydraulic torque wrench. The stepped plane and the force-bearing surface of the wrench rod can be adjusted to be parallel by rotating the position of the stepped block 6-2 on the cylinder. For wrench rods of different sizes, the stepped planes at different positions can be replaced or the adjustment pads 6-3 can be added to achieve parallel offset between the stepped plane and the force-bearing surface of the wrench rod.

It should be noted that each time the hydraulic torque wrench is tested, the bolt simulation device 4 needs to be unloaded to restore the deformation of the butterfly spring to the initial state.

Since the bolt simulation device 4 is provided in the present invention, the movement of the bolt can be simulated well in the detection process, thereby ensuring that the detection of the hydraulic torque wrench is closer to the actual torque value. A stepped block assembly 6 is also provided to provide a reliable reaction arm for wrench bars of different sizes.

Claims (7)

1. a hydraulic torque wrench verification device, comprising a housing, a sensor installed in the housing and a reaction arm assembly installed on the housing, and the output end of the sensor is connected with an external digital display by a cable; it is characterized in that: A bolt simulation device is arranged at the input end of the sensor, and the bolt simulation device includes a square head bolt, two disc springs and a hexagonal nut; The hole is sleeved on the square head bolt through the round hole; the hexagonal nut and the square head bolt are threadedly connected; Extrusion space; the end of the square head bolt protrudes from the hexagonal nut. 2. A hydraulic torque wrench verification device as claimed in claim 1, characterized in that: the height at which the end of the square head bolt extends out of the hexagonal nut is L, and a pitch of the square head bolt thread is P, It is required that L≤P. 3 . The hydraulic torque wrench verification device according to claim 2 , wherein the height of the compression space of the disc spring is h, and h≧P. 4 . 4. A hydraulic torque wrench verification device according to claim 1, wherein the reaction arm assembly is a stepped block assembly, comprising a fixed seat and a stepped block, and the fixed seat includes a A cylinder at the upper end of the square body, the bottom end of the square body is fixedly connected to the shell; the through hole in the center of the stepped stopper is sleeved on the outside of the cylinder of the fixed seat to form a clearance fit; the outer contour of the stepped stopper includes a section of A circular arc and two or more steps, the circular arc is concentric with the through hole, the distance between the plane of the adjacent steps and the center of the through hole is gradually distributed, and the connecting line between the stepped plane and the center of the through hole is perpendicular to the stepped plane. 5 . The hydraulic torque wrench verification device according to claim 4 , wherein the stepped planes have the same length. 6 . 6. A hydraulic torque wrench verification device as claimed in claim 4, characterized in that: the stepped block assembly is further provided with an adjustment pad; the adjustment pad is an L-shaped plate, and the adjustment pad is The width is adapted to the length of the stepped plane. 7 . The hydraulic torque wrench verification device according to claim 1 , wherein the hexagonal nut is sleeved with a sleeve, one end of the sleeve is a hexagonal opening, and the other end is a square opening. 8 .

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