Tightening mechanism, tightening device and tightening system

Abstract

The utility model relates to a tightening mechanism, a tightening device and a tightening system. The tightening mechanism comprises a tightening shaft, a connecting block, a sleeve, a first elastic ring and a second elastic ring, the connecting block is provided with a through hole, the through hole is used for being connected with the sleeve and the tightening shaft in a sleeving mode so that the sleeve and the tightening shaft can be mutually fixed, the sleeve can rotate along with the tightening shaft, and the first elastic ring and the second elastic ring are arranged in the through hole at intervals; the first elastic ring and the second elastic ring are used for being clamped between the periphery of the sleeve and the inner wall of the connecting block, and the sleeve can deviate from the axis of the sleeve and swing by 360 degrees relative to the tightening shaft and extrude the first elastic ring and the second elastic ring. By the adoption of the technical scheme, the sleeve can deviate from the axis to adjust the posture, and therefore the position difference between the sleeve and the bolt is absorbed in the bolt absorbing process; in addition, the sleeve can be prevented from drooping under the supporting action of the first elastic ring and the second elastic ring, and therefore the tightening mechanism can be suitable for bolt installation and tightening operation in any direction.

Description

Technical Field

[0001] The present application relates to the technical field of parts assembly, and in particular to a tightening mechanism, a tightening device and a tightening system. Background Art

[0002] In the field of parts assembly, automatic tightening equipment is generally required during the bolt tightening process.

[0003] In the related art, automatic tightening equipment generally includes air-blowing multi-axis variable pitch style and magnetic multi-axis variable pitch style.

[0004] However, the air-blowing multi-axis variable pitch automatic tightening equipment needs to use a clamp to grab the bolt, which will cause the problem of insufficient opening space for the clamp in narrow places; the magnetic multi-axis variable pitch style is suitable for narrow spaces. In order to eliminate the position error between the tightening sleeve and the bolt and improve the fault tolerance when vertically sucking the bolt, the tightening sleeve of the magnetic multi-axis variable pitch style is generally movably connected relative to the tightening shaft. In this way, when tightening the bolt in the horizontal direction, the tightening sleeve will sag, causing the bolt to be tightened incorrectly and the bolt cannot be put into the bolt hole. Therefore, the automatic tightening effect of the automatic tightening equipment in the related art is poor. Summary of the invention

[0005] Based on this, it is necessary to provide a tightening mechanism, a tightening device and a tightening system to address the problem that the automatic tightening effect of the automatic tightening equipment in the related art is poor.

[0006] On the one hand, the present application provides a tightening mechanism, including a tightening shaft, a connecting block, a sleeve, a first elastic ring and a second elastic ring, the connecting block having a through hole, the through hole being used to respectively sleeve the sleeve and the tightening shaft so that the sleeve and the tightening shaft are fixed to each other and the sleeve can rotate with the tightening shaft, the first elastic ring and the second elastic ring are arranged at intervals in the through hole, and the first elastic ring and the second elastic ring are used to be clamped between the outer periphery of the sleeve and the inner wall of the connecting block, the sleeve can deviate from its axis and swing 360° relative to the tightening shaft in all directions and squeeze the first elastic ring and the second elastic ring.

[0007] By adopting the above technical solution, the sleeve can deviate from its axis and swing 360° in all directions relative to the tightening shaft and squeeze the first elastic ring and the second elastic ring, so that the sleeve can adjust its posture in time when absorbing the bolt, absorb the position difference between the sleeve and the bolt, thereby improving the success rate of bolt absorption; in addition, when the tightening mechanism is horizontally tightened, the sleeve can remain horizontal without sagging under the balanced support of the first elastic ring and the second elastic ring, which helps to avoid the problem of misalignment during the tightening process and the problem of the bolt not being able to fit into the bolt hole. Therefore, the above tightening mechanism can be applied to bolt installation and tightening operations in any direction, which helps to improve the tightening effect.

[0008] In one of the embodiments, the connecting block is provided with a first clamping structure and a second clamping structure on the hole wall in the through hole at intervals, the outer ring surface of the tightening shaft is provided with a clamping groove, the first clamping structure is used to clamp in the clamping groove, the sleeve is provided with a flange, and the second clamping structure is used to abut against the flange.

[0009] In one embodiment, the sleeve is recessed with a first mounting groove, the first elastic ring is arranged in the first mounting groove, the connecting block is further provided with a second mounting groove on the hole wall in the through hole, and the second elastic ring is arranged in the second mounting groove.

[0010] In one embodiment, when the sleeve deviates from its axis and swings 360° relative to the tightening shaft and squeezes the first elastic ring and the second elastic ring, the sleeve can deviate from the axial direction of the tightening shaft by a preset floating amount d, and the value range of the preset floating amount d is less than or equal to 0.6 mm.

[0011] In one embodiment, the connection block is in a gradually expanding shape with an outer diameter gradually increasing along its axial direction, and the end of the connection block with a relatively small diameter is used for sleeve-connecting the sleeve.

[0012] In one of the embodiments, a magnetic attraction groove is provided at one end of the sleeve away from the tightening shaft, and the magnetic attraction groove is used for magnetically attracting the bolt.

[0013] On the other hand, the present application provides a tightening device, which includes the above-mentioned tightening mechanism and also includes a first driving mechanism, which is connected to the tightening mechanism and is used to drive the tightening mechanism to move along the axial direction of the tightening shaft.

[0014] In one embodiment, the tightening device further includes a second driving mechanism, and the second driving mechanism is used to drive the tightening mechanism to move along a planar direction perpendicular to the axis of the tightening shaft.

[0015] On the other hand, the present application also provides a tightening system, which includes the above-mentioned tightening device and a loading device, wherein the loading device is used to load the bolts, and the tightening device is used to accurately align and pick up the bolts.

[0016] In one embodiment, the number of each of the tightening mechanism, the first driving mechanism and the second driving mechanism is at least two, and each of the tightening mechanisms is configured with one first driving mechanism and one second driving mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the structure of a tightening device in one embodiment of the present application.

[0018] Figure 2 for Figure 1 Enlarged view of the tightening device shown at A.

[0019] Figure 3 This is a simplified structural diagram of a tightening mechanism in one embodiment of the present application.

[0020] Figure 4 for Figure 3 An enlarged view of the tightening mechanism shown at B.

[0021] Figure 5 This is a simplified structural diagram of a tightening mechanism in another embodiment of the present application.

[0022] Figure 6 for Figure 5 An enlarged view of the tightening mechanism at C is shown.

[0023] Figure 7 This is a simplified structural diagram of a tightening mechanism in yet another embodiment of the present application.

[0024] Figure 8 for Figure 7 An enlarged view of the tightening mechanism shown at D.

[0025] 10. Tightening device; 11. Tightening mechanism; 12. First driving mechanism; 13. Second driving mechanism; 13a. Driving cylinder; 13b. Sliding assembly; 100. Tightening shaft; 100a. Slot; 200. Connecting block; 200a. Through hole; 200b. Second mounting slot; 210. First clamping structure; 220. Second clamping structure; 300. Sleeve; 300a. First mounting slot; 300b. Magnetic slot; 310. Flange; 400. First elastic ring; 500. Second elastic ring. DETAILED DESCRIPTION

[0026] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0027] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply 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 a limitation on the present application.

[0028] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0029] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0030] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0031] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0032] See also Figure 1 and Figure 2 , Figure 1 FIG. 1 shows a schematic structural diagram of a tightening device 10 in an embodiment of the present application. Figure 2 for Figure 1 An enlarged view of the tightening device 10 at point A is shown.

[0033] The tightening device 10 of the present application can be applied to various assembly lines that require automatic tightening of bolts. In some embodiments, the tightening device 10 includes a tightening mechanism 11 and a first driving mechanism 12, the first driving mechanism 12 is connected to the tightening mechanism 11, and the first driving mechanism 12 is used to drive the tightening mechanism 11 to move along the axial direction of the tightening mechanism 11. Specifically, the tightening mechanism 11 includes a tightening shaft 100, and the axial direction of the tightening mechanism 11 refers to the axial direction of the tightening shaft 100. The first driving mechanism 12 is used to drive the tightening mechanism 11 to move in a vertical downward direction in the bolt suction area to absorb the bolt, and to drive the tightening mechanism 11 to move toward the screw hole to tighten the bolt.

[0034] In some embodiments, the tightening device 10 can be applied to bolt tightening scenarios of parts such as automobile shells. Specifically, the automobile shell to be tightened is placed on an assembly line and moved. At this time, the tightening device 10 can first suck the bolts in the bolt suction area in a vertical downward direction using the tightening mechanism 11, and then move to the vicinity of the automobile shell, and adjust the position of the tightening mechanism 11 through the second driving mechanism 13 to align with the bolt holes on the shell to perform the bolt tightening operation.

[0035] Combination Figure 2 As shown, a tightening mechanism 11 provided in an embodiment of the present application includes a tightening shaft 100, a connecting block 200, a sleeve 300, a first elastic ring 400 and a second elastic ring 500. The connecting block 200 has a through hole 200a, and the through hole 200a is used to respectively sleeve the sleeve 300 and the tightening shaft 100, so that the sleeve 300 and the tightening shaft 100 are fixed to each other and the sleeve 300 can rotate with the tightening shaft 100. The first elastic ring 400 and the second elastic ring 500 are arranged at intervals in the through hole 200a, and the first elastic ring 400 and the second elastic ring 500 are used to be clamped between the sleeve 300 and the connecting block 200, so that the sleeve 300 can deviate from its axis and swing 360° in all directions relative to the tightening shaft (100) and squeeze the first elastic ring 400 and the second elastic ring 500.

[0036] Combination Figure 5-Figure 8 As shown, by adopting the above technical solution, the sleeve 300 can deviate from its axis and swing 360° in all directions relative to the tightening shaft (100) and squeeze the first elastic ring 400 and the second elastic ring 500, so that the sleeve 300 can adjust its posture in time when sucking the bolt, absorb the position difference between the sleeve 300 and the bolt, thereby improving the success rate of sucking the bolt; in addition, combined with Figure 5 As shown, when the tightening mechanism 11 is tightened horizontally, the sleeve 300 can remain horizontal without sagging under the balanced support of the first elastic ring 400 and the second elastic ring 500, which helps to avoid the problem that the bolt and the bolt hole are misaligned during the tightening process of the sleeve 300, and the bolt cannot be inserted into the bolt hole. Therefore, the tightening mechanism 11 can be applied to bolt installation and tightening operations in any direction, which helps to improve the tightening effect.

[0037] Specifically, the elastic strength of the first elastic ring 400 and the second elastic ring 500 can be designed according to the weight of the sleeve 300, so as to ensure that the first elastic ring 400 and the second elastic ring 500 can stably support the sleeve 300 under horizontal tightening conditions; and when vertically sucking the bolt, the sleeve 300 can smoothly squeeze the first elastic ring 400 and the second elastic ring 500 to adjust the posture, thereby ensuring the success rate of suction.

[0038] Combination Figure 2 As shown, in some embodiments, a magnetic suction groove 300b is provided at one end of the sleeve 300 away from the tightening shaft 100, and the magnetic suction groove 300b is used to magnetically attract the bolt, thereby realizing the bolt suction by magnetic attraction. Compared with the traditional method of grabbing the bolt with a clamp, the problem of insufficient opening space of the clamp in a narrow space is avoided, thereby helping to improve the application range of the tightening mechanism 11.

[0039] Combination Figure 2As shown, in some embodiments, the connecting block 200 is provided with a first clamping structure 210 and a second clamping structure 220 on the hole wall in the through hole 200a, and the outer ring surface of the tightening shaft 100 is provided with a clamping groove 100a, the first clamping structure 210 is used to clamp in the clamping groove 100a, the sleeve 300 is provided with a flange 310, and the second clamping structure 220 is used to abut the flange 310, so that the sleeve 300 and the tightening shaft 100 can be locked and fixed in the through hole 200a, and the structure is simple and reliable.

[0040] Specifically, the first clamping structure 210 is a protruding structure protruding from the hole wall, and the second clamping structure 220 is a flange protruding from the hole wall, and the flange of the second clamping structure 220 abuts against the flange 310 of the sleeve 300. In some embodiments, the first clamping structure 210 can be a circular arc surface protruding structure that can be elastically retracted on the hole wall, so that when the connecting block 200 is sleeved on the tightening shaft 100, the first clamping structure 210 can automatically pop up at the position of the clamping groove 100a to complete the clamping, which helps to improve the simplicity of assembly.

[0041] Continue to combine Figure 2 As shown, in some embodiments, the sleeve 300 is recessed with a first mounting groove 300a, the first elastic ring 400 is arranged in the first mounting groove 300a, the connecting block 200 is further provided with a second mounting groove 200b on the hole wall in the through hole 200a, and the second elastic ring 500 is arranged in the second mounting groove 200b, thereby realizing the installation and positioning of the first elastic ring 400 and the second elastic ring 500.

[0042] Specifically, in this embodiment, the first mounting groove 300a and the second mounting groove 200b are spaced apart along the axial direction of the tightening mechanism 11, and the first mounting groove 300a is arranged on the side close to the tightening shaft 100, and the second mounting groove 200b is arranged on the side away from the tightening shaft 100. In the process of the sleeve 300 squeezing the first elastic ring 400 and the second elastic ring 500, the squeezing effect of the sleeve 300 on the second elastic ring 500 is much greater than the squeezing effect on the first elastic ring 400. Therefore, the second mounting groove 200b is provided on the hole wall of the connecting block 200, so that the plane integrity of the squeezing part of the sleeve 300 can be ensured, thereby ensuring the squeezing effect of the sleeve 300 on the second elastic ring 500; and the first mounting groove 300a is provided on the sleeve 300, so that the positioning effect of the sleeve 300 on the first elastic ring 400 can be improved, thereby ensuring the supporting effect of the first elastic ring 400 on the sleeve 300 in the first mounting groove 300a.

[0043] In some embodiments, when the sleeve 300 deviates from its axis and swings 360° in all directions relative to the tightening shaft (100) and squeezes the first elastic ring 400 and the second elastic ring 500, the sleeve 300 can deviate from the axial direction of the tightening shaft 100 by a preset floating amount d, and the preset floating amount d is less than or equal to 0.6 mm.

[0044] Specifically, combined Figure 5 and Figure 6 As shown, the floating amount d refers to the horizontal displacement of the end position of the sleeve 300 close to the magnetic groove 300b from its original vertical position. It can also be understood as the difference between the radius of the circle where the end of the sleeve 300 close to the magnetic groove 300b is at the maximum deviation when the sleeve 300 deviates from its axis and the radius of the sleeve 300. By limiting the preset floating amount d, it is possible to prevent the swing amplitude of the sleeve 300 from being too large, thereby ensuring working reliability.

[0045] Combination Figure 2-Figure 8 As shown, in some embodiments, the connecting block 200 is gradually expanded along its axial direction with the outer diameter gradually increasing, and the end of the connecting block 200 with a relatively small diameter is used to socket the sleeve 300, so that it can ensure that the volume occupied by the connecting block 200 is reduced, thereby increasing the depth of the connecting block 200 when extending into a narrow space to send the bolt into the bolt hole, and further improving the adaptability to the working environment of the narrow space.

[0046] The present application also provides a tightening device 10, which includes the tightening mechanism 11 of any of the above-mentioned embodiments.

[0047] Combination Figure 1 As shown, in some embodiments, the tightening device 10 further includes a first driving mechanism 12 , which is connected to the tightening mechanism 11 , and is used to drive the tightening mechanism 11 to move along the axial direction of the tightening shaft 100 .

[0048] In some embodiments, the tightening device 10 further includes a second driving mechanism 13, which is used to drive the tightening mechanism 11 to move along a plane direction perpendicular to the axis of the tightening shaft 100, thereby realizing the hole-matching operation of the tightening mechanism 11 and improving the success rate of bolt tightening.

[0049] In some embodiments, the second driving mechanism 13 of the tightening device 10 includes a driving cylinder 13a and a sliding assembly 13b. The tightening mechanism 11 is connected to the sliding assembly 13b. The driving cylinder 13a is used to move the tightening mechanism 11 on the sliding assembly 13b to drive the tightening mechanism 11 to move.

[0050] Specifically, the sliding assembly 13b can be in the form of a slider and a slide rail, or a slider and a slide rod. The use of cylinder pitch change is conducive to streamlining the structure, while reducing production costs and improving economic benefits. It should be noted that the traditional magnetic-style automatic tightening equipment uses electric cylinder pitch change, which has a complex pitch change form and a limited range of application. The present application achieves the goal of a streamlined structure and can be used in narrow spaces by using a cylinder drive combined with a magnetic gripper bolt, which is conducive to promotion and application.

[0051] The present application also provides a tightening system, which includes the above-mentioned tightening device 10 and a loading device. The loading device is used to load bolts, and the tightening device 10 is used to accurately align and pick up the bolts, thereby achieving full automation from picking up the bolts to tightening process, thereby improving work efficiency.

[0052] Specifically, the loading device can transfer the bolt to a preset position so as to be precisely aligned with the tightening device 10 , and the tightening device 10 moves close to the bolt and automatically picks it up.

[0053] In some embodiments, the number of the tightening mechanisms 11, the first drive mechanisms 12, and the second drive mechanisms 13 is at least 2, and each tightening mechanism 11 is equipped with a first drive mechanism 12 and a second drive mechanism 13. Specifically, the number of tightening mechanisms 11, the first drive mechanisms 12, and the second drive mechanisms 13 can be 2, 4, or 7, etc., and the specific number can be set according to the actual application scenario. In addition, by configuring each tightening mechanism 11 with a first drive mechanism 12 and a second drive mechanism 13, independent control of the tightening mechanism 11 can be achieved, thereby improving the control accuracy and flexibility of the tightening device 10.

[0054] Furthermore, in some embodiments, the tightening system further includes a third driving mechanism (not shown) and a mounting frame (not shown), the third driving mechanism is used to connect with the mounting frame, the tightening device 10 is distributed on the mounting frame according to preset positions, and the third driving mechanism is used to drive the mounting frame to move, so as to change the various orientations of the tightening device 10 in space, thereby realizing the tightening operation of the tightening device 10 in various orientations. For example, when the tightening device 10 is used to absorb the bolt, the third driving mechanism is used to drive the mounting frame to move, so that each tightening device 10 is vertically downward; when the tightening device 10 is used to perform a tightening operation horizontally, the third driving mechanism drives the mounting frame to move, so as to adjust the tightening device 10 to be horizontal and facing the corresponding bolt hole.

[0055] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0056] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A tightening mechanism, characterized in that: The tightening mechanism includes a tightening shaft, a connecting block, a sleeve, a first elastic ring and a second elastic ring. The connecting block has a through hole, and the through hole is used to respectively sleeve the sleeve and the tightening shaft so that the sleeve and the tightening shaft are fixed to each other and the sleeve can rotate with the tightening shaft. The first elastic ring and the second elastic ring are arranged at intervals in the through hole, and the first elastic ring and the second elastic ring are used to be clamped between the outer periphery of the sleeve and the inner wall of the connecting block. The sleeve can deviate from its axis and swing 360° relative to the tightening shaft in all directions and squeeze the first elastic ring and the second elastic ring.

2. The tightening mechanism according to claim 1, characterized in that: The connecting block is provided with a first clamping structure and a second clamping structure on the hole wall in the through hole at intervals, the outer ring surface of the tightening shaft is provided with a clamping groove, the first clamping structure is used to clamp in the clamping groove, the sleeve is provided with a flange, and the second clamping structure is used to abut against the flange.

3. The tightening mechanism according to claim 1, characterized in that: The sleeve is recessed with a first mounting groove inwardly, the first elastic ring is arranged in the first mounting groove, the connecting block is further provided with a second mounting groove on the hole wall in the through hole, and the second elastic ring is arranged in the second mounting groove.

4. The tightening mechanism according to claim 1, characterized in that: When the sleeve deviates from its axis and swings 360° relative to the tightening shaft and squeezes the first elastic ring and the second elastic ring, the sleeve can deviate from the axial direction of the tightening shaft by a preset floating amount d, and the value range of the preset floating amount d is less than or equal to 0.6 mm.

5. The tightening mechanism according to claim 1, characterized in that: The connecting block is in a gradually expanding shape with an outer diameter gradually increasing along its axial direction, and an end of the connecting block with a relatively small diameter is used for sleeve-connecting the sleeve.

6. The tightening mechanism according to claim 1, characterized in that: A magnetic attraction groove is provided at one end of the sleeve away from the tightening shaft, and the magnetic attraction groove is used for magnetically attracting the bolt.

7. A tightening device, characterized in that: The tightening device comprises the tightening mechanism according to any one of claims 1 to 6, and further comprises a first driving mechanism, wherein the first driving mechanism is connected to the tightening mechanism and is used to drive the tightening mechanism to move along the axial direction of the tightening shaft.

8. The tightening device according to claim 7, characterized in that: The tightening device further comprises a second driving mechanism, and the second driving mechanism is used to drive the tightening mechanism to move along a plane direction perpendicular to the axis of the tightening shaft.

9. A tightening system, characterized in that: The tightening system includes the tightening device according to claim 8, and also includes a loading device, wherein the loading device is used to load the bolts, and the tightening device is used to accurately align and pick up the bolts.

10. The tightening system according to claim 9, characterized in that: The number of the tightening mechanisms, the first driving mechanisms, and the second driving mechanisms is at least two, and each of the tightening mechanisms is configured with one first driving mechanism and one second driving mechanism.

Images