A strut-type lower lock detection device and detection method

Abstract

The application provides a bracing rod type lower lock detection device and a detection method. The bracing rod type lower lock detection device comprises a pressure load joint, a left tension load joint, a right tension load joint, two stand plates arranged at intervals and two limiting pins respectively connected to two ends of the stand plates; the stand plates and the limiting pins are connected to form a fully open mounting space; the two ends of the stand plates are further connected with a bolt; a measuring sliding block is arranged at the middle part of the two stand plates, and the measuring sliding block can be extended and retracted relative to the stand plates to the mounting space. The application can realize the pressure load test of the bracing rod lock on the press and the tension load test on the test bench, and provides reliable data for the bracing rod type lower lock.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aircraft landing gear performance detection, and particularly relates to a strut type lower lock detection device and detection method. BACKGROUND

[0002] The strut type lower lock is a support type detachable strut lock structure with eccentricity, which is used for connecting a front strut and a fuselage component. After locking, the front strut can bear the heading and vertical load, so as to realize load transmission between the front strut and the fuselage component. After unlocking, the strut type lower lock can work coordinately with the front strut and be retracted into a front landing gear cabin. The realization of the above characteristics mainly depends on the L1 size between the center of the hinge hole of the upper strut assembly and the lower strut assembly and the center of the connecting hole at the two ends of the strut lock. The change of the L1 size will affect the stability of the strut lock bearing.

[0003] In order to verify that the strut type lower lock is installed on the aircraft and ensure the safe operation of the aircraft, the performance and function of the pulling and pressing load must be verified before delivery.

[0004] Therefore, it is necessary to provide a device and method for effectively verifying the performance detection of the strut type lower lock. SUMMARY

[0005] The present application aims to provide a strut type lower lock detection device and detection method, which can realize the pressing load test of the strut lock on the pressing machine and the pulling load test on the test bench, and provide reliable data for the strut type lower lock.

[0006] The technical scheme of the present application is as follows: a strut type lower lock detection device comprises a pressing load connector, a pulling load left connector, a pulling load right connector, two spaced-apart vertical plates, and two limiting pins respectively connected to the two ends of the vertical plates; the vertical plates and the limiting pins are connected to form a fully open mounting space; the two ends of the vertical plates are further connected with a bolt; a measuring slide block is arranged at the middle part of the two vertical plates, and the measuring slide block can be extended and retracted relative to the vertical plates into the mounting space;

[0007] When the pressing load test is performed, the pressing load connectors are arranged at the two ends of the vertical plates and are respectively mounted on the bolts, and a centering pin for slidingly being mounted in the center hole of the upper and lower workbenches of the pressing machine is arranged on the pressing load connector; the extension direction of the measuring slide block is perpendicular to the connecting line of the axis center lines of the two pressing load connectors;

[0008] When the pulling load test is performed, the pulling load left connector and the pulling load right connector are respectively arranged at the two ends of the vertical plates and are respectively mounted on the bolts, and the extension direction of the measuring slide block is perpendicular to the connecting line of the axis center lines of the pulling load left connector and the pulling load right connector.

[0009] The support rod type lower lock detection device positions and fixes the lower lock at the tension and compression center of the test equipment; the middle part of the detection device is provided with a hinge bolt connecting the upper support rod assembly, the lower support rod assembly, the rocking arm hinge hole, the measuring block and the measuring sliding block; the detection device can realize the detection of the eccentricity of the support rod type lower lock when bearing the tension load and the compression load by replacing the connecting joint.

[0010] The eccentricity detection device of the present application can realize the compression load test of the support rod lock on the press and the tension load test on the test bench by replacing the joint, and provide reliable data for the support rod lock.

[0011] Two centering pins are designed, which are respectively installed in pressure with the two compression load joints and are matched with the center hole gap of the upper and lower workbench of the press, so that the center of the press and the center of symmetry of the support rod type lower lock are coincided, and the detection error is reduced.

[0012] Preferably, the support rod type lower lock detection device further comprises a spring, a stud, a bracket and a support, the support is connected to the bottom of the two vertical plates at the same time, one side of the support is an A surface, and the side away from the vertical plate is a B surface; the measuring sliding block is arranged on the A surface, and the measuring sliding block is in sliding fit with the inner side walls of the two vertical plates; the bracket is arranged on the B surface and protrudes towards the measuring sliding block, the stud is arranged on the protruding end of the bracket, and the stud extends into the measuring sliding block; the spring is sleeved on the stud and abuts against the measuring sliding block and the bracket respectively.

[0013] The support rod type lower lock detection device can effectively detect the change of the eccentricity of the support rod type lower lock when bearing the tension load and the compression load.

[0014] Preferably, the measuring sliding block is U-shaped, the bottom edge of the measuring sliding block is used for installing the stud, the two vertical side edges are respectively in sliding fit with the two vertical plates, and the extended end with an opening extends into the installation space.

[0015] The U-shaped structure design can reduce the contact area of the measuring sliding block and the measuring block, and improve the detection accuracy when sliding.

[0016] Preferably, the plug pin is provided with a stepped surface capable of positioning the end surface of the ear piece of the support rod type lower lock. The stepped surface can be matched with the round nut to realize effective locking.

[0017] Preferably, the vertical plate is provided with an open waist-shaped groove, and the plug pin is matched with the waist-shaped groove. The open waist-shaped groove is beneficial to the installation and disassembly of the support rod type lower lock, and is convenient and fast.

[0018] Preferably, one end of the centering pin is in H7 / r6 pressure fit with the compression load joint, and the other end is in H8 / f7 gap fit with the center hole of the upper and lower workbench of the press.

[0019] The application also provides a strut-type lower lock detection method, which is performed by using the strut-type lower lock detection device.

[0020] Perform the compression load test:

[0021] Step one, make the strut-type lower lock in the locked state, and do not install the safety pin; pass a pin through the double lug hole of the upper strut of the strut-type lower lock, the compression load connector, and the vertical plate;

[0022] Step two, pass another pin through the double lug hole of the lower strut of the strut-type lower lock, the compression load connector, and the vertical plate;

[0023] Step three, tighten the measuring block on the hinge bolt of the hinged upper strut assembly, the lower strut assembly, and the rocker arm; the connecting line of the axial lines of the two compression load connectors forms a distance L1 with the center line of the measuring block;

[0024] Step four, adjust the distance between the upper and lower workbenches of the press machine, so that the centering pin on the compression load connector is slidingly installed in the center hole of the upper and lower workbenches of the press machine;

[0025] Step five, adjust the position of the measuring sliding block so that it is in contact with the measuring block;

[0026] Step six, adsorb the dial gauge on the side of the vertical plate, and the dial gauge head is close to the end surface of the measuring sliding block away from the measuring block, and adjust the dial gauge pointer to the "0" position;

[0027] Step seven, simultaneously apply a compression load to the installation space in the direction of both ends of the detection device, and keep for a certain period of time, and check the deformation and loss of the strut-type lower lock structure; at this time, the hinge bolt and the measuring block are stressed, driving the measuring sliding block to slide along the bracket, checking the change amount of the dial gauge pointer, and checking whether the safety pin on the strut-type lower lock can be installed and removed again;

[0028] Step eight, make the strut-type lower lock under inspection in the locked state, install the safety pin, and repeat step seven to check whether the safety pin can be removed and installed again; complete the compression load test;

[0029] Perform the tension load test:

[0030] Step nine, install the left tension load connector and the right tension load connector on the pin respectively, and connect the left tension load connector and the right tension load connector to the test bench respectively;

[0031] Repeat steps one to three and steps five to six of the compression load test;

[0032] Step ten, make the strut lower lock in the locked state, do not install the safety pin, simultaneously apply a pulling load to the far away from the installation space at both ends of the detection device and keep for a certain time, check the deformation and loss of the strut lower lock structure, check the change of the dial indicator pointer, and check whether the safety pin on the strut lower lock can be installed and removed again;

[0033] Step eleven, make the strut lower lock in the locked state, install the safety pin; repeat step ten, and check whether the safety pin can be removed and installed again; complete the pulling load test;

[0034] The above-mentioned compression load test and pulling load test have no sequence.

[0035] Preferably, in the step three, the L1=5.3±0.3mm is checked.

[0036] Preferably, in the step, the change of the dial indicator pointer is L1≯0.9mm.

[0037] Compared with the related art, the present application has the following beneficial effects:

[0038] I. The detection device can detect the change of the eccentricity L1 and the change of the strut lower lock components when the strut lower lock of an aircraft is in the locked state, installs the safety pin and does not install the safety pin, and bears the pulling load and the compression load respectively; after the test is completed, the safety pin can be smoothly installed and removed, and the stability of the strut lower lock is verified;

[0039] II. The overall structure of the detection device is convenient to disassemble and assemble, and the main parts are connected by threads; after the connector is replaced, the device can be used for function test between the compression machine and the test bench in cooperation with the strut lower lock;

[0040] III. For similar products, only the plug and the connector need to be replaced to detect the eccentricity, and technical support and reliable guarantee are provided for the development and test of the same type of strut lower lock. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 The structure schematic view of the strut lower lock detection device provided by the present application is shown in the figure;

[0042] Figure 2 The bottom view of Figure 1 ;

[0043] Figure 3 The schematic view of the strut lower lock detection device provided by the present application when the eccentricity compression load detection is performed;

[0044] Figure 4 The schematic view of the strut lower lock detection device provided by the present application when the eccentricity pulling load detection is performed;

[0045] Figure 5Structure diagram of the limiting pin in Figure 1 ;

[0046] Figure 6 Structure diagram of the upper pin in Figure 1 ;

[0047] Figure 7 Structure diagram of the lower pin in Figure 1 ;

[0048] Figure 8 Structure diagram of the vertical plate in Figure 1 ;

[0049] Figure 9 Structure diagram of the measuring slider in Figure 1 ;

[0050] Figure 10 Structure diagram of the bracket in Figure 1 ;

[0051] Figure 11 Structure diagram of the support in Figure 1 ;

[0052] Figure 12 Structure diagram of the support in Figure 1 ;

[0053] Figure 13 Structure diagram of the left pulling load joint in Figure 1 ;

[0054] Figure 14 Structure diagram of the right pulling load joint in Figure 1 ;

[0055] Figure 15 Structure diagram of the hinge bolt in Figure 1 . DETAILED DESCRIPTION

[0056] The present application will be described in detail below with reference to the drawings and in conjunction with embodiments. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. For the convenience of description, if the terms “upper”, “lower”, “left” and “right” appear in the following, they only mean the same as the upper, lower, left and right directions of the drawings, and do not limit the structure.

[0057] As Figure 1As shown, the support rod type lower position lock detection device provided by the embodiment comprises a round nut 1, a hexagonal nut 2, a limiting pin 3, a centering pin 4, a ballast joint 5, an upper bolt 6, a vertical plate 7, a stepped screw 8, a first screw 9, a measuring slider 10, a spring 11, a stud 12, a second screw 13, a bracket 14, a support 15, a measuring block 16, a hinged bolt 17, a lower bolt 18, a left load pulling joint 19, and a right load pulling joint 20.

[0058] The vertical plate 7 is provided in two, as Figure 9 As shown, the vertical plate 7 comprises a long straight wall and a short plate extending vertically along both ends of the long straight plate, thereby forming a U shape. The two corners of the long straight plate and the short plate are provided with matching holes 72 matched with the limiting pin 3, and the short plate is provided with waist-shaped grooves 71 opening to the right side, and the depth of the right waist-shaped groove 71 is greater than that of the left waist-shaped groove 71.

[0059] As Figure 5 As shown, the limiting pin 3 comprises a third body segment 31, a fifth matching segment 32, and a third threaded segment 33. The fifth matching segment 32 is connected with the third body segment 31, the third threaded segment 33 is connected with the fifth matching segment 32, and the fifth matching segment 32 and the third threaded segment 33 are provided symmetrically at both ends of the third body segment 31. The diameter of the fifth matching segment 32 is smaller than that of the third body segment 31, so that the end face of the third body segment 31 forms a third step face 34 capable of being attached to the vertical plate 7. During installation, the third body segment 31 is located between the two vertical plates 7, and the third step face 34 abuts the inner side wall of the two vertical plates 7, respectively. The fifth matching segment 32 is matched with the matching hole 72, and the third threaded segment 33 extends out of the vertical plate 7 and is fixed by being screwed with the hexagonal nut 2. In this way, the vertical plate 7 and the limiting pin 3 are connected to form a fully open installation space for clamping the support rod type lower position lock. The fully open installation space facilitates installation and adjustment.

[0060] The bolt comprises the upper bolt 6 and the lower bolt 18. The upper bolt 6 is installed on the left side of the vertical plate 7, and the lower bolt 18 is installed on the right side of the vertical plate 7. As Figure 7 As shown, the upper bolt 6 is sequentially provided with a first matching segment 63, a first body segment 62, a second matching segment 64, a first threaded segment 65, and a first plug-in segment 66 from right to left. The diameter of the first body segment 62 is greater than that of the second matching segment 64, so that the left side of the first body segment 62 forms a first step face 61.

[0061] As Figure 8As shown, the lower pin 18 is sequentially provided with a third matching section 183, a second body section 182, a fourth matching section 184, a second threaded section 185 and a second inserting section 186 from right to left. The left side of the second body section 182 is radially protruded to form a second step surface 181.

[0062] As shown in the drawings, the upper pin 6 is installed by inserting the ear hole of the upper support rod assembly of the support rod lock into the upper pin 6, and positioning the first step surface 61 against the end surface of the ear of the upper support rod assembly. At this time, the second matching section 61 is matched with the ear hole. The round nut 1 is sleeved, and the round nut 1 is matched with the first threaded section 65 and locks the upper support rod assembly on the upper pin 6. Figure 1 、 Figure 3 、 Figure 7 As shown in the drawings, the lower pin 18 is installed by inserting the ear hole of the lower support rod assembly of the support rod lock into the lower pin 18, and positioning the second step surface 181 against the end surface of the ear of the lower support rod assembly. At this time, the fourth matching section 184 is matched with the ear hole. The round nut 1 is sleeved, and the round nut 1 is matched with the second threaded section 185 and locks the lower support rod assembly on the lower pin 18. The corresponding step surface is designed to facilitate the locking of the round nut.

[0063] As shown in the drawings, the lower pin 18 is installed by inserting the ear hole of the lower support rod assembly of the support rod lock into the lower pin 18, and positioning the second step surface 181 against the end surface of the ear of the lower support rod assembly. At this time, the fourth matching section 184 is matched with the ear hole. The round nut 1 is sleeved, and the round nut 1 is matched with the second threaded section 185 and locks the lower support rod assembly on the lower pin 18. The corresponding step surface is designed to facilitate the locking of the round nut. Figure 1 、 Figure 3 、 Figure 8 As shown in the drawings, the lower pin 18 is installed by inserting the ear hole of the lower support rod assembly of the support rod lock into the lower pin 18, and positioning the second step surface 181 against the end surface of the ear of the lower support rod assembly. At this time, the fourth matching section 184 is matched with the ear hole. The round nut 1 is sleeved, and the round nut 1 is matched with the second threaded section 185 and locks the lower support rod assembly on the lower pin 18. The corresponding step surface is designed to facilitate the locking of the round nut.

[0064] The first matching section 63 and the first inserting section 66 are respectively inserted into the waist-shaped hole 71 on the left side of the vertical plate 7, and the third matching section 183 and the second inserting section 186 are respectively inserted into the waist-shaped hole 71 on the right side of the vertical plate 7. The structure design of the open waist-shaped hole 71 allows the upper and lower pins to slide when the support rod type lower lock bears the pulling and pressing load, which is convenient for installation and disassembly.

[0065] As shown in the drawings, the support 15 is connected to the bottom of two vertical plates 7, and one side of the support 15 is an A surface, and the side away from the vertical plate 7 is a B surface. Figure 3 As shown in the drawings, the measuring slider 10 is U-shaped, and the bottom edge is used to install the stud 12, and the extended end 101 with an opening extends into the installation space. The end surface of the measuring slider 10 is provided with a through waist-shaped hole 102. The measuring slider 10 is installed on the A surface through the stepped screw 8, so that the vertical two side edges of the U-shaped measuring slider 10 are respectively slidably matched with the inner side walls of the two vertical plates 7. The stepped screw 8 has a smooth surface section and a threaded section, the smooth surface section is gap matched with the measuring slider 10 through the waist-shaped hole 102, and the threaded section is threadedly connected with the threaded hole 151 of the support 15 (as shown in the drawings).

[0066] Figure 3 、 Figure 10 As shown in the drawings, the measuring slider 10 is U-shaped, and the bottom edge is used to install the stud 12, and the extended end 101 with an opening extends into the installation space. The end surface of the measuring slider 10 is provided with a through waist-shaped hole 102. The measuring slider 10 is installed on the A surface through the stepped screw 8, so that the vertical two side edges of the U-shaped measuring slider 10 are respectively slidably matched with the inner side walls of the two vertical plates 7. The stepped screw 8 has a smooth surface section and a threaded section, the smooth surface section is gap matched with the measuring slider 10 through the waist-shaped hole 102, and the threaded section is threadedly connected with the threaded hole 151 of the support 15 (as shown in the drawings).​Figure 12 As shown). Figure 12 As shown, the support 15 has a through hole 152, and the first screw 9 is inserted into the hole 152 to install the support 15 in the middle section of the two upright plates 7. The other end plate of the support 15 has a hole (unlabeled) for the second screw 13 to pass through, as shown... Figure 3 As shown, four screws 13 are used to mount the two brackets 14 onto the support 15. On the end plate of the same support 15, the support 15 is fixed to the bottom of the upright plate 7 by bolts.

[0067] like Figure 3 , Figure 11 As shown, the bracket 14 is L-shaped, with one side disposed on the B-surface and the other side protruding towards the measuring slider 10. A stud 12 is disposed on the protruding end of the bracket 14, and the stud 12 is threaded into the measuring slider 10. The spring 11 is sleeved on the stud 12 and abuts against both the measuring slider 10 and the bracket 14.

[0068] During the load test, the load connector 5 is located at both ends of the vertical plate 7 and is respectively installed on the upper pin 6 and the lower pin 18. The load connector 5 is provided with a centering pin 4 for sliding installation in the center holes of the upper and lower worktables of the press 21. Figure 6 As shown, the head of the load-bearing connector 5 is provided with a hole 51 for installing a positioning pin. The extension and retraction direction of the measuring slider 10 is perpendicular to the line connecting the centerlines of the two load-bearing connectors 5. One end of the centering pin 4 is in H7 / r6 press fit with the load-bearing connector 5, and the other end is in H8 / f7 clearance fit with the center hole of the upper and lower worktables of the press 21. After the load-bearing test is completed, no more force is applied to the upper and lower worktables of the press. The round nut 1 is loosened, and the upper pin 6, lower pin 18, and load-bearing connector 5 are removed from the waist-shaped groove 71 of the vertical plate 7.

[0069] During the tensile load test, the left tensile load connector 19 is installed on the upper pin 6, and the right tensile load connector 20 is installed on the lower pin 18. The extension and retraction direction of the measuring slider 10 is perpendicular to the line connecting the center lines of the left tensile load connector 19 and the right tensile load connector 20.

[0070] like Figure 13 As shown, the left tensile load connector has an internal thread 191 that connects to the test bench thread. The internal thread hole M72X2-6H of the left tensile load connector connects to the external thread of the left connector of the test bench. The right end is connected to the lug hole of the upper support rod assembly of the support rod lock through the upper pin 6. Figure 14As shown, the right joint of the pull load is provided with external thread 201 which is screwed with the test bench. The external thread M80X2-6g of the right joint of the pull load is connected with the internal thread of the test bench, and the left end is connected with the ear of the lower strut assembly of the strut lock through the lower pin 18.

[0071] As shown, the measuring slider 10 is tightly attached to the measuring block 16 under the action of the spring 11 (in the elongated state) before force is applied. The measuring block 16 is screwed on the hinge bolt 17 (as shown in Figure 2 The measuring block 16 is screwed on the hinge bolt 17 (as shown in Figure 15 After the strut lock is stressed, the size L1 changes, and the measuring block 16 drives the measuring slider 10 to slide along the upper surface of the support 15, at which time the spring 11 is compressed along the stud 12.

[0072] The application also provides a strut type lower lock detection method, which is performed by using the above strut type lower lock detection device, and comprises the following steps:

[0073] The compression load test is performed (as shown in Figure 3

[0074] Step S1, the strut type lower lock is in the locked state, and no safety pin is installed; one pin is inserted through the double-ear hole of the upper strut of the strut type lower lock, the compression load joint 5 and the vertical plate 7;

[0075] Step S2, another pin is inserted through the double-ear hole of the lower strut of the strut type lower lock, the compression load joint 5 and the vertical plate 7;

[0076] Step S3, the measuring block 16 is screwed on the hinge bolt 17 of the hinge upper strut assembly, the hinge lower strut assembly and the rocker arm; two circular nuts 1 shown in the figure are screwed respectively. The connecting line of the axial lines of the two ends of the compression load joint 5 is spaced apart from the center line of the measuring block 16 by a distance L1; the distance L1 is checked to be 5.3±0.3mm (the delivery state of the strut type lower lock); at this time, the strut lock is completely positioned in the detection device; Figure 1

[0077] Step S4, the distance between the upper and lower worktables of the press 21 is adjusted, so that the centering pin 4 on the compression load joint 5 is slidingly installed in the center hole of the upper and lower worktables of the press 21 (as shown in Figure 1 At this time, the center of the connecting line of the ear hole of the upper and lower strut assemblies of the strut lock coincides with the pressure center of the press;

[0078] Step S5, the position of the measuring slider 10 is adjusted, so that the extension end 101 of the measuring slider 10 is in contact with the measuring block 16;

[0079] Step S6, the dial gauge is adsorbed on the side C of the vertical plate 7 (as shown in Figure 4 The head of the dial gauge is tightly attached to the end surface D (as shown in​​Figure 4 (As shown), adjust the dial indicator pointer to the "0" position;

[0080] Step S7, simultaneously move both ends of the detection device toward the installation space (e.g., Figure 2 Apply a compressive load (in the direction of the arrow shown) and maintain it for a certain period of time (no less than 1 minute) to check the deformation and damage of the strut-type lower lock structure; at this time, the hinge bolt 17 and the measuring block 16 are under force, which drives the measuring slider 10 to slide along the bracket 14. Check that the change in the dial indicator pointer, i.e., L1, is ≤0.9mm, and check whether the safety pin on the strut-type lower lock can be installed and then removed (the safety pin needs to pass through the double-ear fork hole and the connecting rod hole of the upper strut assembly, such as...). Figure 2 (location shown at point E)

[0081] Step S8: Ensure the lower locking lever is locked, install the safety pin, repeat step seven, and then check if the safety pin can be removed and reinstalled; complete the load test.

[0082] Perform tensile load tests (such as) Figure 4 (as shown)

[0083] Step S9: Install the left tension load connector 19 and the right tension load connector 20 on the pin respectively, and connect the left tension load connector 19 and the right tension load connector 20 to the test bench respectively.

[0084] Steps S1~S3 and S5~S6 during repeated load tests;

[0085] Step S10: Lock the strut-type lower lock without installing the safety pin, and simultaneously apply a tensile load of 9500 mm at both ends of the detection device, moving away from the installation space. +2500 N, and hold for a certain period of time (no less than 1 minute) to check the deformation and damage of the strut-type lower lock structure, check that the change in the dial indicator pointer, i.e., L1, is ≤0.9mm, and check whether the safety pin on the strut-type lower lock can be installed and then removed.

[0086] Step S11: Ensure the lower locking lever is locked and install the safety pin; repeat step S10 to check if the safety pin can be removed and reinstalled; complete the tensile load test.

[0087] The above-mentioned compressive load test and tensile load test have no specific order;

[0088] Step S12: Loosen the round nut 1, remove the upper pin 6 and lower pin 18 from the upright plate 7, remove the testing device and strut lock from the test bench, and finally remove the left tension load connector 19 and the right tension load connector 20. The entire test is now complete.

[0089] After the compression and tension tests are completed, the L1 value should meet the requirements and the safety pin should be able to be installed and removed.

[0090] The above merely illustrates the embodiments of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation, or direct or indirect application in other related technical fields, which is made according to the content of the specification and drawings of the present application, is also included in the patent protection scope of the present application.

Claims

1. A strut-type lower position lock detection device, characterized in that, It includes a compressive load connector (5), a tensile load left connector (19), a tensile load right connector (20), two spaced vertical plates (7), and two limiting pins (3) respectively connected to the two ends of the two vertical plates (7); the vertical plates (7) and the limiting pins (3) are connected to form a fully open installation space; the two ends of the vertical plates (7) are also connected with pins; a measuring slider (10) is provided in the middle of the two vertical plates (7), and the measuring slider (10) can extend and retract relative to the vertical plates (7) into the installation space; During the load test, the load joint (5) is set at both ends of the upright plate (7) and installed on the pins respectively. The load joint (5) is provided with a centering pin (4) for sliding installation in the center hole of the upper and lower worktables of the press. The extension and retraction direction of the measuring slider (10) is perpendicular to the line connecting the center lines of the two load joints (5). During the tensile load test, the left tensile load connector (19) and the right tensile load connector (20) are respectively set at both ends of the upright plate (7) and respectively installed on the pin. The extension and retraction direction of the measuring slider (10) is perpendicular to the line connecting the center lines of the left tensile load connector (19) and the right tensile load connector (20).

2. The strut-type lower position lock detection device according to claim 1, characterized in that, It also includes a spring (11), a stud (12), a bracket (14), and a support (15). The support (15) is connected to the bottom of both upright plates (7), and one side of the support (15) is surface A, and the side away from the upright plate (7) is surface B. The measuring slider (10) is disposed on surface A, and the measuring slider (10) slides in cooperation with the inner sidewall of the two upright plates (7). The bracket (14) is disposed on surface B and protrudes in the direction of the measuring slider (10). The stud (12) is disposed on the protruding end of the bracket (14), and the stud (12) extends into the measuring slider (10). The spring (11) is sleeved on the stud (12) and abuts against the measuring slider (10) and the bracket (14) respectively.

3. The strut-type lower lock detection device according to claim 2, characterized in that, The measuring slider (10) is U-shaped, with its bottom edge used to install the stud (12), and its two vertical sides slidingly engaging with the two upright plates (7) respectively. The extended end with an opening extends into the installation space.

4. The strut-type lower lock detection device according to claim 1, characterized in that, The pin has a stepped surface that can be positioned with the end face of the lug of the strut-type lower lock.

5. The strut-type lower position lock detection device according to claim 1, characterized in that, The upright plate (7) is provided with a waist-shaped groove (71) with one end open, and the pin is engaged with the waist-shaped groove (71).

6. The strut-type lower position lock detection device according to claim 1, characterized in that, One end of the centering pin (4) is in H7 / r6 press fit with the load fitting (5), and the other end is in H8 / f7 clearance fit with the center hole of the upper and lower worktables of the press.

7. A method for detecting a strut-type lower position lock, using the strut-type lower position lock detection device as described in claim 2 or 3, characterized in that... include: Perform a compressive load test: Step 1: Put the strut-type lower position lock in the locked state without installing the safety pin; pass a pin through the double ear hole of the strut-type lower position lock, the load-bearing connector (5), and the upright plate (7); Step 2: Pass another pin through the double-ear hole of the strut-type lower locking strut, the load-bearing connector (5), and the upright plate (7); Step 3: Tighten the measuring block (16) onto the hinge bolt (17) of the hinged upper strut assembly, lower strut assembly and rocker arm; the line connecting the axial lines of the load-bearing joints (5) at both ends forms a distance L1 with the center line of the measuring block (16); Step 4: Adjust the distance between the upper and lower worktables of the press so that the centering pin (4) on the load-bearing connector (5) is slidably installed in the center hole of the upper and lower worktables of the press. Step 5: Adjust the position of the measuring slider (10) so that it contacts the measuring block (16); Step 6: Attach the dial indicator to the side of the upright plate (7), with the dial indicator head close to the end face of the measuring slider (10) away from the measuring block (16), and adjust the dial indicator pointer to the "0" position. Step 7: Apply a compressive load to both ends of the testing device in the direction of the installation space and hold it for a certain period of time to check the deformation and damage of the strut-type lower lock structure. At this time, the hinge bolt (17) and the measuring block (16) are under force, which drives the measuring slider (10) to slide along the bracket (14). Check the change of the dial indicator pointer and check whether the safety pin on the strut-type lower lock can be installed and then removed. Step 8: Ensure the lower locking lever is locked, install the safety pin, repeat step 7, and then check if the safety pin can be removed and reinstalled; complete the load test. Perform tensile load tests: Step 9: Install the left tension load connector (19) and the right tension load connector (20) on the pin respectively, and connect the left tension load connector (19) and the right tension load connector (20) to the test bench respectively; Steps one through three, and steps five through six, during repeated load testing; Step 10: Put the strut-type lower lock in the locked state without installing the safety pin. Simultaneously apply tensile load to both ends of the detection device away from the installation space and maintain it for a certain period of time. Check the deformation and damage of the strut-type lower lock structure, check the change of the dial indicator pointer, and check whether the safety pin on the strut-type lower lock can be installed and then removed. Step 11: Ensure the lower locking lever is locked and install the safety pin; repeat step 10, then check if the safety pin can be removed and reinstalled; complete the tensile load test. The above-mentioned compressive load test and tensile load test have no specific order.

8. The method for detecting a strut-type lower lock according to claim 7, characterized in that, In step three, L1 is checked to be 5.3 ± 0.3 mm.

9. The method for detecting a strut-type lower-position lock according to claim 7, characterized in that, In the aforementioned steps, the change in the dial indicator pointer is L1 ≯ 0.9 mm.

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