Working device stress fatigue test device and test method

Abstract

The invention discloses a working device stress fatigue test device and test method, and belongs to the technical field of excavator stress fatigue test. The working device comprises a movable arm, a bucket rod and a bucket which are connected in sequence; the testing device comprises a T-shaped groove base, a first actuator, a second actuator and a plurality of hydraulic oil cylinders; the movable arm is arranged on the T-shaped groove base; one end of the first actuator and one end of the second actuator are installed on the T-shaped groove base, and the other ends of the first actuator and the second actuator are connected with the bucket and used for applying external force to the bucket. The hydraulic oil cylinder is connected with the movable arm, the bucket rod or the bucket and used for applying external force to the movable arm, the bucket rod or the bucket. Through loading of the actuator and the hydraulic oil cylinder, the stress conditions of the excavator working device under various working conditions are simulated, the test accuracy is improved, and the test time is greatly shortened.

Description

Technical Field

[0001] The invention belongs to the technical field of excavator stress fatigue testing, and in particular relates to a working device stress fatigue testing device and a testing method. Background Art

[0002] Existing stress fatigue testing equipment for excavator working devices often uses two axes and a rigid rod to apply force to the working device for stress fatigue testing. This testing method cannot adjust the forces at each hinge point during the test posture, making it impossible to replicate the stress levels at each part during maximum excavation conditions, leading to inaccurate test results. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a working device stress fatigue test device and test method, which simulates the stress conditions of the excavator working device under various working conditions through loading with actuators and hydraulic cylinders, thereby improving the test accuracy.

[0004] The present invention provides the following technical solutions:

[0005] In a first aspect, a working device stress fatigue test device is provided, wherein the working device comprises a boom, a dipper arm and a bucket connected in sequence.

[0006] The test device includes a T-slot base, a first actuator, a second actuator, and a plurality of hydraulic cylinders;

[0007] The boom is mounted on a T-slot base; one end of the first actuator and the second actuator are mounted on the T-slot base, and the other end is connected to the bucket for applying external force to the bucket;

[0008] The hydraulic cylinders are respectively connected to the boom, the dipper arm or the bucket, and are used to apply external force to the boom, the dipper arm or the bucket.

[0009] As an optional technical solution of the present invention, it also includes a first reaction seat and a second reaction seat;

[0010] The first reaction seat is fixed on the T-slot base and is located on one side of the bucket; one end of the first actuator is connected to the first reaction seat, and the other end is connected to one side of the bucket, for applying force in the rotation direction of the bucket;

[0011] The second reaction seat is fixed on the T-slot base and is located on the tooth tip side of the bucket; one end of the second actuator is connected to the second reaction seat, and the other end is connected to the tooth tip side of the bucket, for applying force to the digging direction of the bucket.

[0012] As an optional technical solution of the present invention, it also includes a boom mounting seat, which is fixed on the T-slot base; one end of the boom is connected to the boom mounting seat.

[0013] As an optional technical solution of the present invention, the multiple hydraulic cylinders include a boom cylinder, an arm cylinder and a bucket cylinder;

[0014] The output end of the boom oil cylinder is connected to the boom, and the other end is connected to the boom mounting seat. The output end of the dipper arm oil cylinder is connected to the dipper arm, and the other end is connected to the boom. The output end of the bucket oil cylinder is connected to the bucket, and the other end is connected to the dipper arm.

[0015] As an optional technical solution of the present invention, the first actuator and the second actuator are provided with force sensors for detecting the digging force of the working device.

[0016] In a second aspect, a test method for the working device stress fatigue test device according to the first aspect is provided, characterized in that it includes an actuator loading test method and a cylinder loading test method;

[0017] The actuator loading test method includes:

[0018] Obtaining true stress and strain data of each measuring point of the working device in a working state;

[0019] In the test device, strain gauges are attached to the same measuring points of the working device to measure stress and strain data;

[0020] Lock all hydraulic cylinders and adjust the output force of the second actuator until the stress and strain data of the working device at the same measuring point are the same as the actual stress and strain data;

[0021] Adjust the magnitude and direction of the output force of the first actuator to simulate the rotational torque of the working device under different loads and postures, and obtain stress and strain data at each measuring point;

[0022] The oil cylinder loading test method includes:

[0023] Obtaining the displacement of the hydraulic cylinder and the maximum pressure value of the hydraulic cylinder when the working device is in a working state;

[0024] In the test device, strain gauges are attached to each measuring point of the working device to measure stress and strain data.

[0025] Adjust the displacement of each hydraulic cylinder in the working device to be the same as the displacement of the hydraulic cylinder when the working device is in the working state;

[0026] Adjust the position of each hydraulic cylinder until the output force of the second actuator is 0;

[0027] Pressurize the hydraulic cylinder in sequence. When the maximum pressure value of the hydraulic cylinder in the working state is reached, the output force of the second actuator is the maximum digging force, and the stress and strain data of each measuring point are obtained.

[0028] As an optional technical solution of the present invention, the step of sequentially pressurizing the hydraulic cylinders so that when the maximum pressure value of the hydraulic cylinders in the working state is reached, the output force of the second actuator becomes the maximum digging force includes:

[0029] Pressurizing the hydraulic cylinder of the bucket, when the maximum pressure value of the hydraulic cylinder of the bucket in the working state is reached, the output force of the second actuator is the maximum digging force of the bucket;

[0030] Retract the output end of the bucket's hydraulic cylinder until the output force of the second actuator is 0, and pressurize the hydraulic cylinder of the boom. When the maximum pressure value of the hydraulic cylinder of the boom is reached in the working state, the output force of the second actuator is the maximum digging force of the boom.

[0031] As an optional technical solution of the present invention, the digging force of the bucket is expressed as:

[0032] ;

[0033] in, Indicates the digging force of the bucket, Indicates the torque of the bucket's hydraulic cylinder on the bucket's tooth tip. Indicates the horizontal component of the vector pointing from the front end of the bucket arm to the tip of the bucket tooth. Represents the vertical component of the vector pointing from the front end of the bucket arm to the tip of the bucket tooth. Indicates the rotation angle of the boom relative to the T-slot base. Indicates the angle of the bucket arm relative to the boom, Indicates the rotation angle of the bucket relative to the arm.

[0034] As an optional technical solution of the present invention, the digging force of the bucket arm is expressed as:

[0035] ;

[0036] in, Indicates the digging force of the bucket arm, Indicates the cylinder diameter of the boom hydraulic cylinder. Indicates the system pressure, Indicates the distance from the hinge point of the hydraulic cylinder of the bucket rod to the hinge point of the front end of the boom. Indicates the distance from the front hinge point of the boom to the front hinge point of the stick. Indicates the distance from the front hinge point of the bucket arm to the tip of the bucket tooth. Indicates the angle between the hydraulic cylinder of the bucket rod and the forward insertion of the boom. It represents the angle between the line from the front hinge point of the bucket arm to the tip of the bucket tooth and the line from the front hinge point of the boom to the front hinge point of the bucket arm.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] The working device stress fatigue testing device provided by the present invention simulates the stress conditions of the excavator working device under various working conditions through loading by an actuator and a hydraulic cylinder, thereby improving the test accuracy and greatly shortening the test time. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 2 is a schematic structural diagram of a stress fatigue test device for a working device according to an embodiment of the present invention;

[0040] Figure 2 Schematic diagram of the parameters of the digging force of the bucket in the embodiment of the present invention

[0041] Figure 3 Schematic diagram of parameter marking of the digging force of the bucket arm in an embodiment of the present invention.

[0042] The following are marked in the figure: 1. Boom; 2. Arm; 3. Bucket; 4. Boom mounting base; 5. Boom cylinder; 6. Arm cylinder; 7. Bucket cylinder; 8. First actuator; 9. Second actuator; 10. First reaction seat; 11. Second reaction seat; 12. T-slot base. DETAILED DESCRIPTION

[0043] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0044] Example 1

[0045] This embodiment provides a working device stress fatigue test device. In this embodiment, the working device adopts the excavating device of an excavator. Figure 1 As shown, the working device includes a boom 1, an arm 2 and a bucket 3 connected in sequence, and the boom 1, the arm 2 and the bucket 3 are connected by a pin shaft.

[0046] The test device includes a T-slot base 12, a first actuator 8, a second actuator 9 and multiple hydraulic cylinders; the boom 1 is installed on the T-slot base 12; one end of the first actuator 8 and the second actuator 9 is installed on the T-slot base 12, and the other end is connected to the bucket 3 for applying external force to the bucket 3; the hydraulic cylinders are respectively connected to the boom 1, the arm 2 or the bucket 3 for applying external force to the boom 1, the arm 2 or the bucket 3.

[0047] The device further includes a first reaction seat 10 and a second reaction seat 11. The first reaction seat 10 is fixed to a T-slot base 12 and is located on one side of the bucket 3. One end of the first actuator 8 is connected to the first reaction seat 10, and the other end is connected to one side of the bucket 3, for applying force in the rotation direction of the bucket 3. The second reaction seat 11 is fixed to the T-slot base 12 and is located on the tooth tip side of the bucket 3. One end of the second actuator 9 is connected to the second reaction seat 11, and the other end is connected to the tooth tip side of the bucket 3, for applying force in the digging direction of the bucket 3. The first actuator 8 and the second actuator 9 are equipped with force sensors for detecting the digging force of the working device. The first actuator 8 and the second actuator 9 provide feedback of the digging force detected by the force sensors.

[0048] It also includes a boom mounting base 4 fixed on the T-slot base 12 ; one end of the boom 1 is connected to the boom mounting base 4 .

[0049] Furthermore, the multiple hydraulic cylinders include a boom cylinder 5, an arm cylinder 6 and a bucket cylinder 7; the output end of the boom cylinder 5 is connected to the boom 1, and the other end is connected to the boom mounting base 4, the output end of the arm cylinder 6 is connected to the arm 2, and the other end is connected to the boom 1, and the output end of the bucket cylinder 7 is connected to the bucket 3, and the other end is connected to the arm 2.

[0050] Example 2

[0051] This embodiment provides a test method for the working device stress fatigue test device described in Example 1, including an actuator loading test method and a cylinder loading test method. The two test methods can be used separately or in combination.

[0052] 1. The actuator loading test method includes:

[0053] Obtaining true stress and strain data of each measuring point of the working device in a working state;

[0054] In the test device, strain gauges are attached to the same measuring points of the working device to measure stress and strain data;

[0055] Lock all hydraulic cylinders and adjust the output force of the second actuator 9 until the stress and strain data of the working device at the same measuring point are the same as the actual stress and strain data;

[0056] The magnitude and direction of the output force of the first actuator 8 are adjusted to simulate the rotational torque of the working device under different loads and different postures, and the stress and strain data of each measuring point are obtained.

[0057] 2. The oil cylinder loading test method includes:

[0058] Obtaining the displacement of the hydraulic cylinder and the maximum pressure value of the hydraulic cylinder when the working device is in a working state;

[0059] In the test device, strain gauges are attached to each measuring point of the working device to measure stress and strain data.

[0060] Adjust the displacement of each hydraulic cylinder in the working device to be the same as the displacement of the hydraulic cylinder when the working device is in the working state;

[0061] Adjust the position of each hydraulic cylinder until the output force of the second actuator 9 is 0;

[0062] The hydraulic cylinder is pressurized in sequence. When the maximum pressure value of the hydraulic cylinder is reached in the working state, the output force of the second actuator 9 is the maximum digging force. The loading and unloading reciprocating cycle is repeated to simulate the working condition of the working device and obtain the stress and strain data of each measuring point.

[0063] The process of sequentially pressurizing the hydraulic cylinder until the maximum pressure value of the hydraulic cylinder in the working state is reached and the output force of the second actuator 9 is the maximum digging force includes:

[0064] Pressurize the hydraulic cylinder of the bucket 3. When the maximum pressure value of the hydraulic cylinder of the bucket 3 is reached in the working state, the output force of the second actuator 9 becomes the maximum digging force of the bucket.

[0065] Retract the output end of the hydraulic cylinder of the bucket 3 until the output force of the second actuator 9 is 0, and pressurize the hydraulic cylinder of the boom 2. When the maximum pressure value of the hydraulic cylinder of the boom 2 is reached in the working state, the output force of the second actuator 9 is the maximum digging force of the boom.

[0066] The digging force of the bucket is expressed as:

[0067] ;

[0068] in, Indicates the digging force of the bucket, Indicates the torque of the bucket's hydraulic cylinder on the bucket's tooth tip. Indicates the horizontal component of the vector pointing from the front end of the bucket arm to the tip of the bucket tooth. Represents the vertical component of the vector pointing from the front end of the bucket arm to the tip of the bucket tooth. Indicates the rotation angle of the boom relative to the T-slot base. Indicates the angle of the bucket arm relative to the boom, Indicates the rotation angle of the bucket relative to the arm, such as Figure 2 shown.

[0069] The digging force of the bucket arm is expressed as:

[0070] ;

[0071] in, Indicates the digging force of the bucket arm, Indicates the cylinder diameter of the boom hydraulic cylinder. Indicates the system pressure, Indicates the distance from the hinge point of the hydraulic cylinder of the bucket rod to the hinge point of the front end of the boom. Indicates the distance from the front hinge point of the boom to the front hinge point of the stick. Indicates the distance from the front hinge point of the bucket arm to the tip of the bucket tooth. Indicates the angle between the hydraulic cylinder of the bucket rod and the forward insertion of the boom. It represents the angle between the line from the front hinge point of the bucket arm to the tip of the bucket tooth and the line from the front hinge point of the boom to the front hinge point of the bucket arm, such as Figure 3 shown.

[0072] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0073] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0074] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A working device stress fatigue test device, characterized by: The working device comprises a boom (1), a dipper arm (2) and a bucket (3) connected in sequence. The test device includes a T-slot base (12), a first actuator (8), a second actuator (9) and a plurality of hydraulic cylinders; The movable arm (1) is mounted on a T-slot base (12); one end of the first actuator (8) and the second actuator (9) are mounted on the T-slot base (12), and the other end is connected to the bucket (3) for applying external force to the bucket (3); The hydraulic cylinders are respectively connected to the boom (1), the dipper arm (2) or the bucket (3) and are used to apply external force to the boom (1), the dipper arm (2) or the bucket (3).

2. The working device stress fatigue testing device according to claim 1, characterized in that: It also includes a first reaction seat (10) and a second reaction seat (11); The first reaction seat (10) is fixed on the T-slot base (12) and is located on one side of the bucket (3); one end of the first actuator (8) is connected to the first reaction seat (10), and the other end is connected to one side of the bucket (3), and is used to apply force to the rotation direction of the bucket (3); The second reaction seat (11) is fixed on the T-slot base (12) and is located on the tooth tip side of the bucket (3); one end of the second actuator (9) is connected to the second reaction seat (11), and the other end is connected to the tooth tip side of the bucket (3), and is used to apply force to the excavation direction of the bucket (3).

3. The working device stress fatigue testing device according to claim 1, characterized in that: It also includes a boom mounting seat (4) fixed on the T-slot base (12); one end of the boom (1) is connected to the boom mounting seat (4).

4. The working device stress fatigue testing device according to claim 3, characterized in that: The plurality of hydraulic cylinders include a boom cylinder (5), an arm cylinder (6), and a bucket cylinder (7); The output end of the boom oil cylinder (5) is connected to the boom (1), and the other end is connected to the boom mounting base (4); the output end of the dipper rod oil cylinder (6) is connected to the dipper rod (2), and the other end is connected to the boom (1); the output end of the bucket oil cylinder (7) is connected to the bucket (3), and the other end is connected to the dipper rod (2).

5. The working device stress fatigue testing device according to claim 3, characterized in that: The first actuator (8) and the second actuator (9) are provided with force sensors for detecting the digging force of the working device.

6. A test method for the working device stress fatigue test device according to any one of claims 1 to 5, characterized in that: Including actuator loading test method and cylinder loading test method; The actuator loading test method includes: Obtaining true stress and strain data of each measuring point of the working device in a working state; In the test device, strain gauges are attached to the same measuring points of the working device to measure stress and strain data; Lock all hydraulic cylinders and adjust the output force of the second actuator (9) until the stress and strain data of the working device at the same measuring point are the same as the actual stress and strain data; Adjusting the magnitude and direction of the output force of the first actuator (8) to simulate the rotational torque of the working device under different loads and different postures, and obtaining stress and strain data of each measuring point; The oil cylinder loading test method includes: Obtaining the displacement of the hydraulic cylinder and the maximum pressure value of the hydraulic cylinder when the working device is in a working state; In the test device, strain gauges are attached to each measuring point of the working device to measure stress and strain data. Adjust the displacement of each hydraulic cylinder in the working device to be the same as the displacement of the hydraulic cylinder when the working device is in the working state; Adjust the position of each hydraulic cylinder until the output force of the second actuator (9) is 0; The hydraulic cylinder is pressurized in sequence. When the maximum pressure value of the hydraulic cylinder in the working state is reached, the output force of the second actuator (9) is the maximum digging force, and stress and strain data of each measuring point are obtained.

7. The working device stress fatigue test method according to claim 6, characterized in that: The step of sequentially pressurizing the hydraulic cylinder so that when the maximum pressure value of the hydraulic cylinder in the working state is reached, the output force of the second actuator (9) is the maximum digging force, includes: Pressurizing the hydraulic cylinder of the bucket (3), when the maximum pressure value of the hydraulic cylinder of the bucket (3) is reached in the working state, the output force of the second actuator (9) is the maximum digging force of the bucket; The output end of the hydraulic cylinder of the bucket (3) is retracted until the output force of the second actuator (9) is 0, and the hydraulic cylinder of the boom (2) is pressurized. When the maximum pressure value of the hydraulic cylinder of the boom (2) in the working state is reached, the output force of the second actuator (9) is the maximum digging force of the boom.

8. The working device stress fatigue test method according to claim 7, characterized in that: The digging force of the bucket is expressed as: ； in, Indicates the digging force of the bucket, Indicates the torque of the bucket's hydraulic cylinder on the bucket's tooth tip. Indicates the horizontal component of the vector pointing from the front end of the bucket arm to the tip of the bucket tooth. The vertical component of the vector pointing from the front end of the bucket arm to the bucket tooth tip, Indicates the rotation angle of the boom relative to the T-slot base. Indicates the angle of the bucket arm relative to the boom, Indicates the rotation angle of the bucket relative to the arm.

9. The working device stress fatigue test method according to claim 7, characterized in that: The digging force of the bucket arm is expressed as: ； in, Indicates the digging force of the bucket arm, Indicates the cylinder diameter of the boom hydraulic cylinder. Indicates the system pressure, Indicates the distance from the hinge point of the hydraulic cylinder of the bucket rod to the hinge point of the front end of the boom. Indicates the distance from the front hinge point of the boom to the front hinge point of the stick. Indicates the distance from the front hinge point of the bucket arm to the tip of the bucket tooth. Indicates the angle between the hydraulic cylinder of the bucket rod and the forward insertion of the boom. It represents the angle between the line from the front hinge point of the bucket arm to the tip of the bucket tooth and the line from the front hinge point of the boom to the front hinge point of the bucket arm.

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