Heavy-duty car cab getting-on and getting-off man-machine size measuring device and using method

Abstract

The invention provides a heavy-duty car cab getting-on and getting-off man-machine size measuring device and a using method, and relates to the technical field of vehicle detection. The device comprises a horizontal measuring scale, a vertical measuring scale and a first sliding block. The first sliding block is provided with a horizontal guide structure matched with the horizontal measuring scale and a vertical guide structure matched with the vertical measuring scale. Telescopic connecting rods are arranged on the horizontal measuring ruler and located on the two sides of the first sliding block respectively, one end of each connecting rod is in sliding connection with the horizontal measuring ruler, a first locking mechanism is arranged between the horizontal measuring ruler and the corresponding connecting rod, and a fixing mechanism used for being connected with a getting-on handrail is arranged at the other end of each connecting rod. A second sliding block is arranged on the vertical measuring scale and located below the horizontal measuring scale in a sliding mode, a stepping measuring scale is arranged on the second sliding block in a sliding mode, and the stepping measuring scale can slide relative to the second sliding block in the direction perpendicular to the horizontal measuring scale and the vertical measuring scale. The device is small in measurement error, simple and convenient to use, low in cost and short in period.

Description

Technical Field

[0001] The invention relates to the technical field of vehicle detection, in particular to a device for measuring the dimensions of people getting on and off a heavy-duty vehicle cab and a method for using the device. Background Art

[0002] In order to adapt to the large-horsepower engine size and chassis design of heavy-duty trucks, the cab of heavy-duty trucks is currently positioned at a relatively high height. It is necessary to set up multiple steps and use the handrails arranged on both sides of the cab door to achieve getting on and off the vehicle. Human-machine comfort during getting on and off the vehicle is an important part of the cab layout design and human-machine comfort design. Researching and analyzing the key ergonomic dimensions of getting on and off different vehicles has important reference value for optimizing the layout of the cab steps and handrails and improving the comfort of getting on and off the vehicle.

[0003] At present, there are two main methods for obtaining the key dimensions of human-machine comfort in the commercial vehicle cab:

[0004] 1. Using common measuring tapes and other similar measuring tools, 2-3 people work together to measure and obtain. This method has large measurement errors. First, it is impossible to accurately find the horizontal and vertical directions. Secondly, some key human-machine dimensions cannot be obtained by direct measurement. For example, some need to first find the center line between the left and right handrails and use this as the baseline for measurement. Ordinary measuring tapes and other measuring tools have large measurement errors or even cannot be measured.

[0005] 2. Obtaining outer surface point cloud data through optical scanning and other methods, using scanners and other equipment, and obtaining it by measuring point cloud data. This method is costly, has complicated steps, large workload, and long working cycle. Summary of the invention

[0006] In response to the above problems, the present application provides a device for measuring the dimensions of people and machines when getting on and off the cab of a heavy-duty vehicle. The device solves the problem of large measurement errors using ordinary tape measures. At the same time, compared with the optical scanning method, the measuring device is simpler, more convenient, lower in cost, and shorter in cycle.

[0007] The technical solution adopted by the present invention to solve the technical problem is:

[0008] A device for measuring the dimensions of a person getting on and off a heavy-duty vehicle cab, comprising a horizontal measuring ruler, a vertical measuring ruler and a first sliding block for connecting the horizontal measuring ruler and the vertical measuring value;

[0009] The first sliding block is provided with a horizontal guide structure matched with the horizontal measuring ruler and a vertical guide structure matched with the vertical measuring ruler;

[0010] The horizontal measuring ruler is provided with retractable connecting rods on both sides of the first sliding block, one end of the connecting rod is slidably connected to the horizontal measuring ruler, and a first locking mechanism is provided between the horizontal measuring ruler and the connecting rod, and the other end of the connecting rod is provided with a fixing mechanism for connecting to a boarding handrail;

[0011] A second slider is slidably arranged on the vertical measuring ruler below the horizontal measuring ruler, and a step measuring ruler is slidably arranged on the second slider. The step measuring ruler can slide relative to the second slider in a direction perpendicular to the horizontal measuring ruler and the vertical measuring ruler.

[0012] Furthermore, an end of the connecting rod facing away from the horizontal measuring ruler is provided with a mounting groove for accommodating a boarding handrail, and one side or both sides of the mounting groove are provided with a first locking screw for tightening the boarding handrail.

[0013] Furthermore, the connecting rod comprises an outer sleeve and an inner sleeve which are coaxially sleeved, and a second locking mechanism is arranged between the outer sleeve and the inner sleeve.

[0014] Furthermore, a second guide hole matching with the horizontal measuring ruler is provided at one end of the outer sleeve facing the horizontal measuring ruler, and the first locking mechanism is a first tightening bolt provided on the outer sleeve.

[0015] Furthermore, the second locking mechanism is a second locking screw arranged on the outer sleeve.

[0016] Furthermore, a second tightening bolt is provided on the second sliding block, and a sliding groove for accommodating the second tightening bolt is provided on the step measuring scale. When the second tightening bolt is tightened, the end of the second tightening bolt is tightened on the vertical measuring scale, and the head of the second tightening bolt is pressed on the step measuring scale.

[0017] Furthermore, a level is provided on the first sliding block or the horizontal measuring ruler.

[0018] Furthermore, the horizontal measuring ruler, the vertical measuring ruler and the step measuring ruler are all provided with scale marks.

[0019] Furthermore, the zero scale line of the horizontal measuring ruler is located in the middle, and the dimension value gradually increases along both sides of the middle phase.

[0020] A method for using a device for measuring the dimensions of a person getting on and off a heavy-duty vehicle cab comprises the following steps:

[0021] S1, park the vehicle under test on a flat ground;

[0022] S2, connecting the two connecting rods to the handrails on the left and right sides of the door opening of the vehicle cab respectively, and making the horizontal measuring ruler horizontal, and the lower end of the vertical measuring ruler against the ground;

[0023] S3, adjust the connecting rod so that the horizontal measuring ruler is parallel to the vertical plane where the line connecting the left and right boarding handrails is located;

[0024] S4, adjusting the horizontal measuring ruler so that the scale values ​​of the horizontal measuring rulers corresponding to the two connecting rods are the same;

[0025] S5, moving the first slider so that the vertical measuring ruler is close to the middle position of the step of the vehicle to be measured;

[0026] S6, adjusting the height of the second slider so that the step measuring ruler is aligned with the first step of the vehicle to be measured, and adjusting the step measuring ruler so that the end of the step measuring ruler facing the vehicle to be measured is aligned with the inner end of the step of the vehicle to be measured;

[0027] S7, read the reading M of the first slider on the horizontal measuring ruler, and calculate the X-direction offset of the step of the vehicle to be tested from the center of the door opening through the reading M; read the reading of the connecting rod on the horizontal measuring ruler, and the sum of the readings of the two connecting rods on the horizontal measuring ruler is the door opening size of the cab of the vehicle to be tested; read the size reading corresponding to the outer edge of the first step on the step measuring ruler to obtain the depth of the first step; read the reading of the second slider on the vertical measuring ruler to obtain the height of the first step;

[0028] S8, move the first slider to the left to align the step measuring ruler with the left edge of the first step, and read the reading A1 of the first slider on the horizontal measuring ruler at this time, move the first slider to the right to align the step measuring ruler with the right edge of the first step, and read the reading A2 of the first slider on the horizontal measuring ruler at this time, and calculate the width of the first step by A1 and A2;

[0029] S9, repeat the operations from step S6 to S8 to complete the measurement of each level of steps.

[0030] The beneficial effects of the present invention are:

[0031] The embodiment of the present application provides a device for measuring the human-machine dimensions for getting on and off the cab of a heavy-duty vehicle, which can efficiently and accurately measure the key human-machine dimensions that affect the comfort of getting on and off the vehicle through the adjustment and coordination of a horizontal measuring ruler, a vertical measuring ruler, and a step measuring ruler. The device obtains a database of key ergonomic dimensions for reference in engineering design, and can also be used to assist in the definition of human-machine dimensions during product development, providing accurate dimension input for engineering design. Compared with traditional tape measurement and optical scanning methods, the device not only ensures the accuracy of the measurement results, but is also simple and convenient to use, low cost, and short cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic diagram of the three-dimensional structure of a device for measuring the dimensions of a person getting on and off a heavy-duty vehicle cab provided in an embodiment of the present application;

[0033] Figure 2 for Figure 1 A schematic diagram of the enlarged structure of part A;

[0034] Figure 3 for Figure 1 A schematic diagram of the enlarged structure of part B;

[0035] Figure 4 for Figure 1 A schematic diagram of the enlarged structure of the middle C part;

[0036] Figure 5 for Figure 1 A schematic diagram of the enlarged structure of the D part;

[0037] Figure 6 A schematic diagram of the installation status of a device for measuring the dimensions of people getting on and off a heavy-duty vehicle cab provided in an embodiment of the present application.

[0038] In the figure: 1. Level measuring ruler;

[0039] 2. Vertical measuring ruler;

[0040] 3. first slider; 31. body; 32. first wing plate; 33. first hook plate;

[0041] 4. Connecting rod; 41. Outer sleeve; 42. Inner sleeve; 421. Mounting groove; 43. Second locking screw; 44. First locking screw; 45. First tightening bolt;

[0042] 5. second slider; 51. web plate; 52. second wing plate; 53. second hook plate;

[0043] 6. Step measuring ruler; 61. Sliding slot;

[0044] 7. Second tightening bolt;

[0045] 8. Pressing plate;

[0046] 9. Level. DETAILED DESCRIPTION

[0047] In order to enable those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be described in detail below in conjunction with the drawings in the embodiments of the present application, and the described embodiments are only part of the embodiments of the present application, not all of the embodiments. All other embodiments obtained by those skilled in the art without creative work on the basis of the embodiments of the present application shall belong to the protection scope of the present application.

[0048] For the convenience of description, the coordinate system is defined as Figure 1 As shown, the left-right direction is the horizontal direction, the front-back direction is the longitudinal direction, and the up-down direction is the vertical direction.

[0049] like Figure 1 As shown, a device for measuring the dimensions of a person getting on and off a heavy-duty vehicle cab comprises a horizontal measuring ruler 1 extending in a transverse direction, a vertical measuring ruler 2 extending in a vertical direction, and a first slider 3 for connecting the horizontal measuring ruler 1 and the vertical measurement value. The horizontal measuring ruler 1 and the vertical measuring ruler 2 are arranged vertically, and the first slider 3 is provided with a horizontal guide structure matched with the horizontal measuring ruler 1 and a vertical guide structure matched with the vertical measuring ruler 2. The vertical measuring ruler 2 can slide in a vertical direction relative to the first slider 3, and the horizontal measuring ruler 1 can slide in a horizontal direction relative to the first slider 3.

[0050] As a specific implementation method, Figure 2 As shown, the first slider 3 described in this embodiment includes a body 31, and the body 31 is provided with a first guide hole penetrating the body 31 in the vertical direction. The vertical measuring ruler 2 forms a guide match with the first guide hole, and the vertical measuring ruler 2 can slide up and down along the first guide hole. The first guide hole is the vertical guide structure. The upper and lower ends of the body 31 facing the horizontal measuring ruler 1 are respectively provided with a first wing plate 32 extending toward the side of the horizontal measuring ruler 1, and the suspended ends of the first wing plate 32 are respectively provided with a first hook plate 33 extending inwardly (with the side opposite to the two first wing plates 32 as the inner side), and the body 31, the first wing plate 32 and the first hook plate 33 together form a horizontal guide structure matched with the horizontal measuring ruler 1.

[0051] like Figure 1As shown, the horizontal measuring ruler 1 is provided with connecting rods 4 on both sides of the first sliding block 3, and the connecting rods 4 are retractable structures. One end of the connecting rod 4 is slidably connected to the horizontal measuring ruler 1, and a first locking mechanism for connecting and fixing the horizontal measuring ruler 1 and the connecting rod 4 is provided between the horizontal measuring ruler 1 and the connecting rod 4. The other end of the connecting rod 4 is provided with a mounting groove 421 for accommodating a boarding handrail, and one or both sides of the mounting groove 421 are provided with a first locking screw 44 for tightening the boarding handrail.

[0052] As a specific implementation method, Figure 3 and Figure 4 As shown, the connecting rod 4 described in this embodiment includes an outer sleeve 41 and an inner sleeve 42 which are coaxially sleeved. The inner sleeve 42 can slide axially relative to the outer sleeve 41, thereby realizing the telescopic function of the connecting rod 4. A second locking mechanism for connecting and fixing the outer sleeve 41 and the inner sleeve 42 as one is provided between the outer sleeve 41 and the inner sleeve 42. Exemplarily, the second locking mechanism is a second locking screw 43 provided on the outer sleeve 41. By tightening the second locking screw 43 so that it is pressed against the inner sleeve 42, the outer sleeve 41 and the inner sleeve 42 can be locked and fixed, so that the inner sleeve 42 and the outer sleeve 41 cannot move relative to each other. At this time, the length of the connecting rod 4 is fixed.

[0053] As a specific implementation method, Figure 3 As shown, in this embodiment, the end of the outer sleeve 41 facing the level measuring ruler 1 is provided with a second guide hole for accommodating the level measuring ruler 1, and the shape of the second guide hole matches the cross-sectional shape of the level measuring ruler 1 to form a guide fit. The first locking mechanism is a first tightening bolt 45 provided on the outer sleeve 41, and the first tightening bolt 45 is threadedly connected to the outer sleeve 41. When the first tightening bolt 45 is tightened, the first tightening bolt 45 is tightened on the level measuring ruler 1, thereby realizing the locking and fixing of the connecting rod 4.

[0054] Preferably, for ease of operation, the first tightening bolt 45 is a butterfly bolt.

[0055] As a specific implementation, in this embodiment, a first locking screw 44 for tightening the boarding handrail is provided on one side of the installation slot 421.

[0056] like Figure 1As shown, the vertical measuring ruler 2 is provided with a second slider 5 below the horizontal measuring ruler 1 and capable of sliding up and down relative to the vertical measuring ruler 2. The second slider 5 is provided with a step measuring ruler 6 extending in the front-back direction, the step measuring ruler 6 is perpendicular to both the horizontal measuring ruler 1 and the vertical measuring ruler 2, and the step measuring ruler 6 can slide relative to the second slider 5 in a direction perpendicular to the horizontal measuring ruler 1 and the vertical measuring ruler 2, according to Figure 1 The coordinate system shown is that the step measuring ruler 6 can slide along the front-rear direction relative to the second sliding block 5.

[0057] As a specific implementation method, Figure 5 As shown, the second slider 5 described in this embodiment includes a web 51, and the two ends of the web 51 are respectively provided with a second wing plate 52 extending to one side perpendicular to the web 51, and the suspended end of the second wing plate 52 is provided with a second hook plate 53 extending inward (with the side opposite to the two second wing plates 52 as the inner side) perpendicular to the second wing plate 52. The web 51, the second wing plate 52 and the second hook plate 53 together form a space for accommodating the vertical measuring ruler 2, and form a guiding fit with the vertical measuring ruler 2. The second wing plate 52 on one side of the second slider 5 is provided with a second tightening bolt 7, and the second tightening bolt 7 is threadedly connected to the second slider 5. The step measuring ruler 6 is provided with a sliding groove 61 for accommodating the second tightening bolt 7, and the sliding groove 61 is a long strip structure. When the second jacking bolt 7 is tightened, the end of the second jacking bolt 7 is pressed against the vertical measuring ruler 2, and at the same time, the head of the second jacking bolt 7 is pressed against the step measuring ruler 6, so that the second slider 5 is connected and fixed to the vertical measuring ruler 2, and the step measuring ruler 6 and the second slider 5 are connected and fixed. When the second jacking bolt 7 is not tightened, the step measuring ruler 6 and the second slider 5 can slide up and down as a whole along the vertical measuring ruler 2, and the step measuring ruler 6 can slide in a direction perpendicular to the horizontal measuring ruler 1 and the vertical measuring ruler 2, so as to adjust the measuring length.

[0058] Preferably, for ease of operation, the second tightening bolt 7 is a butterfly bolt.

[0059] Furthermore, in order to ensure the reliability of the connection and fixation between the step measuring ruler 6 and the second sliding block 5 , a clamping plate 8 is sleeved on the second tightening bolt 7 between the head of the second tightening bolt 7 and the step measuring ruler 6 .

[0060] Furthermore, if Figure 2 As shown, a level 9 is provided on the first sliding block 3 or the level measuring ruler 1. By providing the level 9, it is convenient to detect whether the level measuring ruler 1 is level during measurement.

[0061] As a specific implementation, the level meter 9 described in this embodiment is fixedly disposed on the first wing plate 32 located on the upper side of the first sliding block 3 in a detachable manner.

[0062] Furthermore, if Figure 1 As shown, the horizontal measuring ruler 1, the vertical measuring ruler 2 and the step measuring ruler 6 are all provided with scale marks.

[0063] Furthermore, the 0 scale line of the horizontal measuring ruler 1 is located in the middle, and the dimension value gradually increases along both sides of the middle phase. The 0 scale line of the vertical measuring ruler 2 is located at the bottom end of the vertical measuring ruler 2, and the 0 scale line of the step measuring ruler 6 is located at the end of the step measuring ruler 6 close to the measured vehicle.

[0064] A method for using a device for measuring the dimensions of a person getting on and off a heavy-duty vehicle cab comprises the following steps:

[0065] S1, park the vehicle under test on a flat surface.

[0066] S2, connect the two connecting rods 4 to the handrails on the left and right sides of the vehicle cab doorway respectively, and make the horizontal measuring ruler 1 horizontal, and the horizontal measuring ruler 1 is higher than the floor plane of the cab, and the lower end of the vertical measuring ruler 2 is against the ground.

[0067] Specifically, the mounting groove 421 of the left connecting rod 4 is inserted into the handrail on the left side of the vehicle's cab door opening, and the mounting groove 421 of the right connecting rod 4 is inserted into the handrail on the right side of the vehicle's cab door opening, and then the height of the two ends of the horizontal measuring ruler 1 is adjusted by observing the spirit level 9 until the horizontal measuring ruler 1 is in a horizontal state, and then the first locking screws 44 on the two inner sleeves 42 are tightened respectively.

[0068] S3, adjust the length of the connecting rod 4 so that the horizontal measuring ruler 1 is parallel to the vertical plane where the left and right boarding handrails are connected, and there is a gap of no less than 20mm between the vertical measuring ruler 2 and the boarding step. After the adjustment is completed, tighten the second locking screw 43 so that the measuring device is as shown in FIG. Figure 6 Installed on the vehicle to be tested as shown.

[0069] S4, adjust the position of the horizontal measuring ruler 1 in the length direction so that the scale values ​​of the horizontal measuring ruler 1 corresponding to the two connecting rods 4 are the same, and the two connecting rods 4 are symmetrical about the 0 scale line of the horizontal measuring ruler 1, and the 0 scale line of the horizontal measuring ruler 1 is located in the middle of the left and right boarding handrails. Then tighten the first tightening bolt 45.

[0070] S5, moving the first sliding block 3 so that the vertical measuring ruler 2 is close to the middle position of the step of the vehicle to be measured.

[0071] S6, adjust the height of the second slider 5 so that the step measuring ruler 6 is aligned with the first step of the vehicle to be measured, then slide the step measuring ruler 6 so that the end of the step measuring ruler 6 facing the vehicle to be measured is aligned with the inner end of the step of the vehicle to be measured, and then tighten the second tightening bolt 7.

[0072] S7, read the reading M of the first slider 3 on the horizontal measuring ruler 1, and calculate the X-direction offset of the step of the vehicle to be tested from the center of the door opening through the reading M; read the reading of the connecting rod 4 on the horizontal measuring ruler 1, the sum of the readings of the two connecting rods 4 on the horizontal measuring ruler 1 is the door opening size of the cab of the vehicle to be tested; read the size reading corresponding to the outer edge of the first-level step on the step measuring ruler 6 to obtain the depth of the first-level step; read the reading of the second slider 5 on the vertical measuring ruler 2 to obtain the height of the first-level step.

[0073] As a specific implementation, the 0 scale line of the horizontal measuring ruler 1 in this embodiment is located in the middle position of the horizontal measuring ruler 1, so the reading M of the first slider 3 on the horizontal measuring ruler 1 is the X-direction offset of the step of the vehicle to be tested from the center of the door opening.

[0074] S8, move the first slider 3 to the left to align the step measuring ruler 6 with the left edge of the first step, and read the reading A1 of the first slider 3 on the horizontal measuring ruler 1. Then move the first slider 3 to the right to align the step measuring ruler 6 with the right edge of the first step, and read the reading A2 of the first slider 3 on the horizontal measuring ruler 1. The width of the first step is calculated by A1 and A2.

[0075] Specifically, if A1 and A2 are located on the same side of the 0 scale line of the horizontal measuring ruler 1, the width of a first step is the absolute value of A1-A2; if A1 and A2 are located on both sides of the 0 scale line of the horizontal measuring ruler 1, the width of a first step is A1+A2.

[0076] S9, repeat the operations from step S6 to S8 to complete the measurement of each level of steps.

[0077] Other embodiments obtained by those skilled in the art by combining, splitting, reorganizing, etc. the embodiments of the present application on the basis of the embodiments provided in the present application do not exceed the protection scope of the present application.

[0078] The above specific implementation methods have detailed the purpose, technical solutions and beneficial effects of the embodiments of the present application. The above are only specific implementation methods of the embodiments of the present application and are not used to limit the protection scope of the embodiments of the present application. That is, any modifications, equivalent substitutions, improvements, etc. made on the basis of the embodiments of the present application should be included in the protection scope of the embodiments of the present application.

Claims

1. A device for measuring the dimensions of a person getting on and off a heavy-duty vehicle cab, characterized in that: It comprises a horizontal measuring ruler (1), a vertical measuring ruler (2) and a first sliding block (3) for connecting the horizontal measuring ruler (1) and the vertical measuring value; The first sliding block (3) is respectively provided with a horizontal guide structure matched with the horizontal measuring ruler (1) and a vertical guide structure matched with the vertical measuring ruler (2); The horizontal measuring ruler (1) is provided with retractable connecting rods (4) on both sides of the first sliding block (3), one end of the connecting rod (4) is slidably connected to the horizontal measuring ruler (1), and a first locking mechanism is provided between the horizontal measuring ruler (1) and the connecting rod (4), and the other end of the connecting rod (4) is provided with a fixing mechanism for connecting to a boarding handrail; A second sliding block (5) is slidably arranged on the vertical measuring ruler (2) below the horizontal measuring ruler (1), and a step measuring ruler (6) is slidably arranged on the second sliding block (5). The step measuring ruler (6) can slide relative to the second sliding block (5) in a direction perpendicular to the horizontal measuring ruler (1) and the vertical measuring ruler (2).

2. A device for measuring the dimensions of a person getting on and off a heavy-duty vehicle cab according to claim 1, characterized in that: An end of the connecting rod (4) facing away from the horizontal measuring ruler (1) is provided with a mounting groove (421) for accommodating a boarding handrail, and one or both sides of the mounting groove (421) are provided with a first locking screw (44) for tightening the boarding handrail.

3. The device for measuring the dimensions of a person getting on and off a heavy-duty vehicle cab according to claim 1 is characterized in that: The connecting rod (4) comprises an outer sleeve (41) and an inner sleeve (42) which are coaxially sleeved, and a second locking mechanism is arranged between the outer sleeve (41) and the inner sleeve (42).

4. The device for measuring the dimensions of a person getting on and off a heavy-duty vehicle cab according to claim 3 is characterized in that: The end of the outer sleeve (41) facing the level measuring ruler (1) is provided with a second guide hole matched with the level measuring ruler (1), and the first locking mechanism is a first tightening bolt (45) provided on the outer sleeve (41).

5. The device for measuring the dimensions of a person getting on and off a heavy-duty vehicle cab according to claim 3 is characterized in that: The second locking mechanism is a second locking screw (43) arranged on the outer sleeve (41).

6. The device for measuring the dimensions of a person getting on and off a heavy-duty vehicle cab according to claim 1 is characterized in that: The second slider (5) is provided with a second tightening bolt (7), and the step measuring ruler (6) is provided with a sliding groove (61) for accommodating the second tightening bolt (7). When the second tightening bolt (7) is tightened, the end of the second tightening bolt (7) is tightened on the vertical measuring ruler (2), and the head of the second tightening bolt (7) is pressed on the step measuring ruler (6).

7. The device for measuring the dimensions of a person getting on and off a heavy-duty vehicle cab according to claim 1 is characterized in that: The first sliding block (3) or the horizontal measuring ruler (1) is provided with a level (9).

8. The device for measuring the dimensions of a person getting on and off a heavy-duty vehicle cab according to claim 1 is characterized in that: The horizontal measuring ruler (1), the vertical measuring ruler (2) and the step measuring ruler (6) are all provided with scale marks.

9. A device for measuring the dimensions of a person getting on and off a heavy-duty vehicle cab according to claim 8, characterized in that: The zero scale line of the horizontal measuring ruler (1) is located in the middle, and the dimension value gradually increases along both sides of the middle phase.

10. A method for using the device for measuring the dimensions of a person getting on and off a heavy-duty vehicle cab as claimed in claims 1 to 9, characterized in that: The following steps are included: S1, park the vehicle under test on a flat ground; S2, connecting the two connecting rods (4) to the handrails on the left and right sides of the door opening of the vehicle cab respectively, and making the horizontal measuring ruler (1) in a horizontal state, and the lower end of the vertical measuring ruler (2) against the ground; S3, adjusting the connecting rod (4) so ​​that the horizontal measuring ruler (1) is parallel to the vertical plane where the line connecting the left and right boarding handrails is located; S4, adjusting the level measuring ruler (1) so that the scale values ​​of the level measuring ruler (1) corresponding to the two connecting rods (4) are the same; S5, moving the first sliding block (3) so that the vertical measuring ruler (2) is close to the middle position of the step of the vehicle to be measured; S6, adjusting the height of the second slider (5) so that the step measuring ruler (6) is aligned with the first step of the vehicle to be measured, and adjusting the step measuring ruler (6) so that the end of the step measuring ruler (6) facing the vehicle to be measured is aligned with the inner end of the step of the vehicle to be measured; S7, reading the reading M of the first slider (3) on the horizontal measuring ruler (1), and calculating the X-direction offset of the step of the vehicle to be tested from the center of the door opening through the reading M, reading the reading of the connecting rod (4) on the horizontal measuring ruler (1), the sum of the readings of the two connecting rods (4) on the horizontal measuring ruler (1) being the door opening size of the cab of the vehicle to be tested, reading the corresponding size reading of the outer edge of the first step on the step measuring ruler (6) to obtain the depth of the first step, and reading the reading of the second slider (5) on the vertical measuring ruler (2) to obtain the height of the first step; S8, move the first slider (3) to the left side so that the step measuring ruler (6) is aligned with the left edge of the first step, and read the reading A1 of the first slider (3) on the horizontal measuring ruler (1) at this time; move the first slider (3) to the right side so that the step measuring ruler (6) is aligned with the right edge of the first step, and read the reading A2 of the first slider (3) on the horizontal measuring ruler (1) at this time, and calculate the width of the first step through A1 and A2; S9, repeat the operations from step S6 to S8 to complete the measurement of each level of steps.

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