Pneumatic crimp device

Abstract

To provide a pneumatic crimp device which is appropriately usable for crimp work for a crimp connection of an aluminum wire or an aluminum alloy wire with a crimp terminal.SOLUTION: A pneumatic crimp device comprises a pair of crimp arms driven by an air pressure for caulking a crimp terminal and a wire. Each of the pair of crimp arms includes a crimp section, a pressure application section, and a pivot section, the crimp section performs caulking on the crimp terminal and the wire by pivoting the pair of crimp arms around the pivot section, and a ratio of a distance between a center of the crimp section which is a point of action and a center of the pivot section which is a point of support and a distance between a center of the pressure application section which is a point of load and the center of the pivot section which is the point of support is made smaller than a ratio of a distance between a center of a crimp section and a center of a pivot section and a distance between a center of a pressure application section and the center of the pivot section in a crimp device for copper wire crimping.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pneumatic crimping device used to crimp a crimp terminal to an electric wire having a conductor made of aluminum or an aluminum alloy. [Background technology]

[0002] Pneumatic crimping devices are lighter than hydraulic crimping devices, and therefore easier to operate. They are also inexpensive, and therefore are widely used as tools for crimping work.

[0003] For example, Patent Document 1 describes an example of a pneumatic crimping device. This pneumatic crimping device is equipped with two dies that use air pressure to crimp a metal terminal onto an electric wire, a receiving portion for the electric wire and the crimp terminal, an air opening / closing valve that drives one of the dies, and a die cover that rotates in conjunction with the valve and covers the die, thereby making it possible to safely protect the fingers of an operator. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 56-022786 [Patent Document 2] Patent No. 7032822 Summary of the Invention [Problem to be solved by the invention]

[0005] However, conventional pneumatic crimping devices, including the device described in Patent Document 1, are used to crimp copper electric wires to crimp terminals, and are difficult to use when crimping aluminum electric wires to crimp terminals. This is because pneumatic crimping devices cannot apply sufficient pressing force to the crimping portion during crimping. For example, as described in Patent Document 2, when crimping an aluminum electric wire, it is necessary to press the aluminum conductor into multiple holes in the crimp terminal or serrations to break the oxidized coating of the electric wire and achieve electrical continuity. However, conventional pneumatic crimping devices cannot generate a large pressing force, and therefore cannot reliably press the aluminum conductor into the holes.

[0006] For this reason, hydraulic crimping devices have been used exclusively for crimping aluminum electric wires. These devices have many problems, such as being heavy and difficult to operate, making them prone to mistakes, taking a relatively long time of about 60 seconds to crimp, resulting in low productivity, and being expensive.

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a pneumatic crimping device that can be suitably used for crimping an aluminum electric wire or an aluminum alloy electric wire to a crimp terminal. [Means for solving the problem]

[0008] According to the present invention, the pneumatic crimping device comprises a pair of crimping arms driven by a driving force for the crimping operation generated by air pressure to crimp crimp terminals and electric wires. Each of the pair of crimping arms has a crimping portion provided at one end of the crimping arm, a pressure applying portion provided at the other end of the crimping arm to which the driving force for the crimping operation is applied, and a pivot portion provided between the crimping portion and the pressure applying portion, and is configured so that the crimping portion crimps the crimp terminals and electric wires by pivoting the pair of crimping arms around the pivot portion, and the ratio L1 / L2 of the distance L1 between the center of the crimping portion (point of application) and the center of the pivot portion (fulcrum) to the distance L2 between the center of the pressure applying portion (point of force) and the center of the pivot portion (fulcrum) is smaller than the ratio L1' / L2' of the distance L1' between the center of the crimping portion and the center of the pivot portion and the distance L2' between the center of the pressure applying portion and the center of the pivot portion in a crimping device for crimping copper wires.

[0009] The crimping arm forms a lever with the center of the crimping part as the point of application, the center of the pressure applying part as the point of force, and the center of the pivot part as the fulcrum. Therefore, by making the ratio L1 / L2 (the distance L1 between the center of the crimping part (point of application) and the center of the pivot part (fulcrum) and the distance L2 between the center of the pressure applying part (point of force) and the center of the pivot part) smaller than the ratio L1' / L2' (the distance L1' between the center of the crimping part (point of application) and the center of the pivot part (fulcrum) and the distance L2' between the center of the pressure applying part (point of force) and the center of the pivot part) of a crimping device for copper wire crimping, the pressing force for the crimping operation generated at the crimping part is greater than that of a crimping device for copper wire crimping. As a result, even when crimping aluminum electric wires with a pneumatic crimping device, sufficient pressing force can be obtained, and the aluminum conductor can be pressed into the multiple holes in the crimp terminal or serration to destroy the oxidized coating of the electric wire and achieve good electrical conductivity in a short time.

[0010] It is preferable that the distance L1 between the center of the crimping portion and the center of the pivot portion is shorter than the distance L1' between the center of the crimping portion and the center of the pivot portion in the crimping device for copper wire crimping. Thereby, the pressing force for the crimping action generated in the crimping portion becomes larger than that in the case of the crimping device for copper wire crimping. However, this is the case where the distance L2 between the center of the pressure application portion (force point) and the center of the pivot portion (fulcrum point) is equal to the distance L2' between the center of the pressure application portion (force point) and the center of the pivot portion (fulcrum point) of the crimping device for copper wire crimping. In the crimping device, from the viewpoint of compatibility of various crimping dies, the distance between the center of the pressure application portion (force point) and the center of the pivot portion (fulcrum point) is often defined as a predetermined constant value. Therefore, in most cases, the pressing force for the crimping action becomes larger by setting the distance L1 < L1'.

[0011] In this case, it is preferable that the distance L1 between the center of the crimping portion and the center of the pivot portion is less than 21.2 mm. Since the general distance L1' in the case of the crimping device for copper wire crimping is 21.2 mm, if the distance L1 is smaller than this, sufficient pressing force can be obtained even when crimping an aluminum electric wire with a pneumatic crimping device. The aluminum conductor can be pressed into a large number of holes provided in the crimping terminal or the serration to break the oxide coating of the electric wire, and good electrical conduction can be obtained in a short time.

[0012] It is also preferable that the ratio L1 / L2 of the distance L1 between the center of the crimping portion and the center of the pivot portion to the distance L2 between the center of the pressure application portion and the center of the pivot portion is less than 0.54. Since the general ratio L1' / L2' in the case of the crimping device for copper wire crimping is approximately 0.54, if the ratio L1 / L2 is smaller than this, sufficient pressing force can be obtained even when crimping an aluminum electric wire with a pneumatic crimping device. The aluminum conductor can be pressed into a large number of holes provided in the crimping terminal or the serration to break the oxide coating of the electric wire, and good electrical conduction can be obtained in a short time.

[0013] It is also preferable that the device further includes a toggle mechanism having a slider to which a driving force for the crimping operation is applied and two links each having one end connected to the other end of the slider, and the other ends of the links of the toggle mechanism are connected to the pressure applying portions of the pair of crimping arms. By using the toggle mechanism, which is a force-boosting mechanism, a greater output can be obtained with a smaller force.

[0014] In this case, it is preferable that the maximum angle formed by the two links of the toggle mechanism is larger than the maximum angle formed by the two links in a crimping device for crimping copper wire. By making the maximum angle formed by the two links larger than the maximum angle formed by the two links in a crimping device for crimping copper wire, the pressing force applied to the pressure application part of the crimping arm is significantly larger than in a crimping device for crimping copper wire. As a result, even when crimping an aluminum electric wire with a pneumatic crimping device, sufficient pressing force can be obtained, and the aluminum conductor can be pressed into the multiple holes provided in the crimp terminal or serration to destroy the oxidized coating of the electric wire and achieve good electrical conductivity in a short time.

[0015] Furthermore, in this case, it is also preferable that the maximum angle formed by the two links exceeds 125.4°. Since the maximum angle formed by the two links in a crimping device for crimping copper wire is generally 125.4°, if the maximum angle is larger than this, sufficient pressing force can be obtained even when crimping an aluminum electric wire with a pneumatic crimping device, and the aluminum conductor can be pressed into the many holes in the crimp terminal or serrations to break down the oxidized coating of the electric wire and achieve good electrical continuity in a short period of time.

[0016] It is also preferable that the boosting force obtained by the operation of the toggle mechanism and the pair of crimping arms is configured to be 1.2 times the boosting force in the crimping device for crimping copper wires. [Effects of the Invention]

[0017] According to the present invention, even when crimping an aluminum electric wire using a pneumatic crimping device, sufficient pressing force can be obtained, and the aluminum conductor can be pressed into the multiple holes provided in the crimp terminal or serration to destroy the oxidized coating of the electric wire, making it possible to obtain good electrical conductivity in a short period of time. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a perspective view showing the overall configuration of the appearance of a pneumatic crimping device according to an embodiment of the present invention; [Figure 2] 2 is a partially perspective side view schematically showing a partial configuration inside a housing of the pneumatic crimping device and a configuration of a crimping die in the embodiment of FIG. 1. FIG. [Figure 3] 2 is a perspective view schematically showing the configuration of a crimping die of the pneumatic crimping device in the embodiment of FIG. 1. FIG. [Figure 4] 2 is a perspective view schematically showing the configuration of a crimping die of the pneumatic crimping device in the embodiment of FIG. 1. FIG. [Figure 5] 2A to 2E are schematic diagrams showing the configuration of the crimping die of the pneumatic crimping device in the embodiment of FIG. 1, respectively; (A) a front view of one crimping arm; (B) a front view of one crimping arm; (C) a bottom view of one crimping arm; (D) a front view of the other crimping arm; and (E) a plan view of the other crimping arm. [Figure 6] 10A and 10B are diagrams for explaining the function of the crimping arm based on the "leverage principle." [Figure 7] 1A and 1B are diagrams for explaining the principle of a toggle mechanism. [Figure 8] 1. FIG. 4 is a diagram for explaining the function of a toggle mechanism in the pneumatic crimping device according to the embodiment of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] FIG. 1 shows a schematic view of the overall external configuration of a pneumatic crimping device according to one embodiment of the present invention, and FIG. 2 shows a schematic view of a portion of the internal configuration of the housing of the pneumatic crimping device according to this embodiment and the configuration of the crimping dies.

[0020] In Fig. 1, 10 denotes a crimping die, 11 denotes a housing in which a drive mechanism for the crimping die 10 is provided, 12 denotes an air hose joint, and 13 denotes a trigger for the crimping operation provided on the housing 11. A toggle mechanism and an air cylinder connected to a pair of crimping arms (first crimping arm 22 and second crimping arm 23) of the crimping die 10 are provided within the housing 11, and pressurized air is supplied to this air cylinder via an air hose connected to the joint 12.

[0021] 2, 14 denotes a piston rod connected to the piston of the pneumatic cylinder, 15 a piston link rotatably connected at one end to the piston rod 14, 16 a connecting arm rotatably connected to the other end of the piston link 15, 17 a slider of a toggle mechanism inserted and fixed into the connecting arm 16, 18 a first link of the toggle mechanism, 19 a second link of the toggle mechanism, 20 a bracket for fixing the crimping die 10 to the housing 11, 21 a spacer inserted between the crimping die 10 and the bracket 20, 22 a first crimping arm of the crimping die 10, and 23 a second crimping arm of the crimping die 10. The first link 18 of the toggle mechanism is integrated with the slider 17 at one end. The second link 19 of the toggle mechanism is rotatably connected to the slider 17 and the first link 18 at a common connecting portion 19c provided at one end of the toggle mechanism.

[0022] The other end of the first link 18 of the toggle mechanism is rotatably connected to a pressure applying portion 22c provided at one end of the first crimping arm 22, and the other end of the second link 19 of the toggle mechanism is rotatably connected to a pressure applying portion 23c provided at one end of the second crimping arm 23. A crimping portion 22a is provided at the other end of the first crimping arm 22, and a pivot portion 22b is provided between the crimping portion 22a and the pressure applying portion 22c of the first crimping arm 22. This first crimping arm 22 is configured to pivot around the pivot portion 22b. A crimping portion 23a is provided at the other end of the second crimping arm 23, and a pivot portion 23b is provided between the crimping portion 23a and the pressure applying portion 23c of the second crimping arm 23. This second crimping arm 23 is configured to pivot around the pivot portion 23b.

[0023] The crimping die 10 is attached to the housing 11 by pivotally attaching a pair of mounting holes 20a and 20b of the bracket 20 to a pair of mounting holes 11a and 11b of the housing 11, respectively. In this state, when the piston rod 14 is linearly driven in the direction of arrow A (up and down in the figure), the connecting arm 16 is driven via the piston link 15 in the direction of arrow B (diagonally up and down in the figure), which drives the slider 17 of the toggle mechanism diagonally up and down in the figure. When the slider 17 is driven in this manner, the driving force is transmitted via the first link 18 and second link 19 of the toggle mechanism to the pressure applying portion 22c of the first crimping arm 22 and the pressure applying portion 23c of the second crimping arm 23, and the first crimping arm 22 and the second crimping arm 23 pivot about the pivot portions 22b and 23b. The crimping operation is performed by driving the crimping portion 22a of the first crimping arm 22 and the crimping portion 23a of the second crimping arm 23 in a direction to close each other, and the crimping operation is completed by driving them in a direction to open each other.

[0024] Figures 3 and 4 show a schematic configuration of the crimping die in this embodiment, with Figure 3 showing the crimping portion in a closed state and Figure 4 showing the crimping portion in an open state. Figure 5 also shows the crimping die in this embodiment in more detail, with (A) showing the first crimping arm 22, the second crimping arm 23, and the spacer 21 as seen from the front, (B) showing the second crimping arm 23 as seen from the front, (C) showing the second crimping arm 23 as seen from the bottom, (D) showing the first crimping arm 22 as seen from the front, and (E) showing the first crimping arm 22 as seen from the top (plan).

[0025] As shown in these figures, the first crimping arm 22 has at one end a crimping portion 22a that crimps the aluminum electric wire and the crimp terminal together, a pressure applying portion 22c at the other end to which a pressing force is applied from the toggle mechanism, and a pivot portion 22b that serves as the center of rotation between the crimping portion 22a and the pressure applying portion 22c. Similarly, the second crimping arm 23 has at one end a crimping portion 23a that crimps the aluminum electric wire and the crimp terminal together, a pressure applying portion 23c at the other end to which a pressing force is applied from the toggle mechanism, and a pivot portion 23b that serves as the center of rotation between the crimping portion 23a and the pressure applying portion 23c.

[0026] Next, the function of the crimping arm based on the "leverage principle" will be described.

[0027] The first crimping arm 22 and the second crimping arm 23 perform crimping operations by the "principle of a lever" with the pivot portions 22b and 23b as fulcrums, respectively. In this case, the centers of the crimping portions 22a and 23a respectively constitute the points of application, the centers of the pressure applying portions 22c and 23c respectively constitute the points of force, and the centers of the pivot portions 22b and 23b respectively constitute the fulcrums.

[0028] 6 explains the function of the "principle of leverage" in this embodiment. Note that the same applies to the second crimping arm 23, so the following explanation will be given taking the first crimping arm 22 as an example.

[0029] As shown in FIG. 6, let the distance between the center (point of action) of the crimping portion 22a of the first crimping arm 22 and the center (fulcrum point) of the pivot portion 22b be L1, and the distance between the center (point of force) of the pressure application portion 22c and the center (fulcrum point) of the pivot portion 22b be L2. In the pneumatic crimping device for aluminum wire crimping of the present invention, since it is required to make the pressing force at the point of action higher than that in the case of the pneumatic crimping device for copper wire crimping, the distance L1 between the point of action and the fulcrum point of each crimping arm needs to be set to a value shorter than the distance L1' in the case of the pneumatic crimping device for copper wire crimping. That is, it is necessary to set L1 < L1'. However, this is the case where the distance L2 between the point of force and the fulcrum point of each crimping arm is defined as a constant value. In fact, from the perspective of the compatibility of the crimping dies, the distance L2 is often set to a constant value (for example, L2 = 39.8 mm).

[0030] The distance L1' between the point of action and the fulcrum point of each crimping arm in the conventional pneumatic crimping device for copper wire crimping is 8 mm 2 In the case of electric wires, L1' = 21.2 mm, and the distance L2' between the point of force and the fulcrum point was L2' = 39.8 mm. Therefore, the distance L1 between the point of action and the fulcrum point in the present embodiment needs to be set such that L1 < L1' = 21.2 mm.

[0031] Regarding the ratio L1 / L2 between the distance L1 between the acting point and the fulcrum of each crimping arm and the distance L2 between the force point and the fulcrum, since the ratio L1' / L2' between the distance L1' between the acting point and the fulcrum of each crimping arm and the distance L2' between the force point and the fulcrum in the pneumatic crimping device for copper wire crimping is L1' / L2' = 21.2 mm / 39.8 mm = approximately 0.54, the ratio L1 / L2 needs to be set to a value smaller than 0.54. That is, it is necessary to set L1 / L2 < L1' / L2' = approximately 0.54. Although it is just an example, in this embodiment, L1 / L2 = 20.5 mm / 39.8 mm = approximately 0.52. Thus, according to the "lever principle", at the acting point of the crimping arm, a force multiplication of 1.94 times can be obtained. Incidentally, in the conventional pneumatic crimping device for copper wire crimping, the force multiplication was 1.88 times. Therefore, the force multiplication of the pneumatic crimping device in this embodiment with respect to the pneumatic crimping device for copper wire crimping due to the function of the crimping arm is 1.94 / 1.88 = 1.03.

[0032] Next, the function of the toggle mechanism in this embodiment will be described.

[0033] Figure 7 illustrates the principle of the toggle mechanism. The toggle mechanism is a kind of link mechanism composed of two links and one slider, and is known to be a force multiplication mechanism similar to a "lever".

[0034] In Figure 7, for the sake of simplicity of explanation, it is assumed that one end TO of one link LINK OA is fixed. The other end TA of this one link LINK OA is not fixed and can move freely in the vertical direction in the figure, and is rotatably connected to one end of the other link LINK AB , and it is also assumed that the other end TB of the other link LINK AB is not fixed and can move freely in the left - right direction in the figure.

[0035] When a force F OA is applied vertically to the other end TA of the link LINK TA , the other end TB of the link LINK AB will have a horizontal force F TBMove horizontally with F TB / F TA The value of LINK OA F TA The angle between the input point TA and the vertical line is α, and the link LINK AB F TA If the angle between the input point TA and the vertical line is β, then F TB / F TA = sinα sinβ / sin(α+β). Link OA Length of the other link LINK AB If the lengths of are equal, then α=β, so F TB / F TA = 1 / 2 (tan α), and increases rapidly as the angle α + β (= 2α) approaches 180°. Therefore, the output force F TB is a small force F TA Even with this input, if the angle α+β (=2α) between the two links approaches 180°, it will become a very large force.

[0036] FIG. 8 shows the configuration of the toggle mechanism in this embodiment.

[0037] As shown in FIG. 8, L3 denotes the distance between the center of the pressure receiving portion 22c of the first crimping arm 22 (connection portion TB1 of the first link 18 in the toggle mechanism) and the center of the pressure receiving portion 23c of the second crimping arm 23 (connection portion TB2 of the second link 19 in the toggle mechanism). L4 denotes the distance between the common connection portion 19c (TA) of the first link 18 and the second link 19 in the toggle mechanism and connection portion TB1 of the first link 18 in the toggle mechanism. L5 denotes the distance between the common connection portion 19c (TA) of the first link 18 and the second link 19 in the toggle mechanism and connection portion TB2 of the second link 19 in the toggle mechanism. Furthermore, L6 denotes the distance between point TC, which is drawn perpendicularly to a line connecting connection portions TB1 and TB2 from the common connection portion TA, and connection portion TB1. L7 denotes the distance between point TC and connection portion TB2. Naturally, L3 = L6 + L7.

[0038] In a conventional pneumatic crimping device for crimping copper wire, distances L3', L4', and L5' were measured when the angle between the first and second links of the toggle mechanism was at its maximum, and L6' and L7' were calculated using Pythagoras' theorem. The results were L3' = 27.0 mm, L4' = 15.0 mm, L5' = 15.4 mm, L6' = 13.3 mm, and L7' = 13.7 mm. The angle θ1 between TB1 and TA and TC was calculated trigonometrically from L4' = 15.0 mm and L6' = 13.3 mm, and the angle θ2 between TB2 and TA and TC was calculated trigonometrically from L5' = 15.4 mm and L7' = 13.7 mm. As a result, θ1=62.5°, θ2=62.9°, and the maximum angle formed by the first link and the second link was θ=θ1+θ2=62.5°+62.9°=125.4°.

[0039] In the pneumatic crimping device for crimping aluminum wires of the present invention, the maximum angle formed by the first link 18 and the second link 19 of the toggle mechanism is set to be larger than that of a pneumatic crimping device for crimping copper wires, thereby increasing the force multiplying effect of the toggle mechanism. Specifically, the maximum angle formed by the first link 18 and the second link 19 of the toggle mechanism is set to a value greater than 125.4°. As a result, even when crimping an aluminum electric wire using a pneumatic crimping device, sufficient pressing force can be obtained, and the aluminum conductor can be pressed into the multiple holes formed in the crimp terminal or serrations to destroy the oxidized coating of the electric wire and achieve good electrical continuity in a short time. As a mere example, in this embodiment, the maximum angle formed by the first link 18 and the second link 19 of the toggle mechanism is set to 132.3°. As a result, the force F output from the toggle mechanism in the crimping device for crimping aluminum wires of this embodiment is TB is 1.13 times the force of the crimping device for copper wire crimping (input force F TA= 1). Taking into account the multiplier of 1.03 due to the "leverage principle" of the crimping arm, the multiplier of the pneumatic crimping device of this embodiment for crimping copper wire is (1.13 / 0.966) x 1.03 = approximately 1.2. The pressing force of the pneumatic crimping device corresponding to the structure of this embodiment and the pressing force of the pneumatic crimping device for crimping copper wire were actually measured. The results are shown in Table 1. The numerical values ​​in the above explanation are for 8 mm 2 The present invention relates to a pneumatic crimping device for electric wires. [Table 1] As can be seen from Table 1, the boost obtained in this embodiment is 8 mm 2 For electric wires, the force is 1.2 times that of the crimping device for copper wire crimping (based on 20.4 / 17.2), and the 2 For electrical wires, the force was 1.5 times (based on 32.2 / 21.6) the force used in the crimping device for copper wire crimping.

[0040] As described above in detail, according to this embodiment, in each crimping arm, the ratio L1 / L2 of the distance L1 between the point of application and the fulcrum to the distance L2 between the point of application and the fulcrum is set smaller than the ratio L1' / L2' of the distance L1' between the point of application and the fulcrum to the distance L2' between the point of application and the fulcrum in a crimping device for crimping copper wire. That is, it is set smaller than the typical ratio L1' / L2' (= approximately 0.54) in a crimping device for crimping copper wire. Furthermore, in the toggle mechanism, the maximum angle formed by the two links is set to exceed the maximum angle formed by the two links in a crimping device for crimping copper wire. That is, it is set to exceed 125.4°, which is the typical maximum angle in a crimping device for crimping copper wire. Due to both the settings of the crimping arm and the toggle mechanism, the pressing force for the crimping operation generated in the crimping portion is significantly greater than in a crimping device for crimping copper wire. As a result, even when crimping aluminum electric wires using a pneumatic crimping device, sufficient pressing force can be obtained, and the aluminum conductor can be pressed into the multiple holes in the crimp terminal or serration, destroying the oxidized coating of the electric wire and achieving good electrical conductivity in a short period of time.

[0041] The above-described embodiments and examples are merely illustrative of the present invention and are not limiting, and the present invention can be embodied in various other modified and altered forms. Therefore, the scope of the present invention is defined only by the claims and their equivalents. [Explanation of symbols]

[0042] 10 Crimping dies 11. Housing 11a, 11b, 20a, 20b Mounting holes 12 Air hose joint 13 Crimping trigger 14 Piston rod 15 Piston link 16 Connecting arm 17 Slider 18 First Link 19 Second Link 19c Common connection part 20 Bracket 21 Spacer 22 First crimping arm 22a, 23a Crimping section 22b, 23b pivot 22c, 23c Pressure entry section 23 Second crimping arm

Claims

1. The crimping device is provided with a pair of crimping arms that are driven by a driving force for crimping operation generated by air pressure and that crimp the crimp terminal and the electric wire, and each of the pair of crimping arms has a crimping portion provided at one end of the crimping arm, a pressure applying portion provided at the other end of the crimping arm and to which the driving force for crimping operation is applied, and a pivot portion provided between the crimping portion and the pressure applying portion, and is configured so that the crimping portion crimps the crimp terminal and the electric wire by pivoting the pair of crimping arms around the pivot portion, and the distance L between the center of the crimping portion, which is the point of action, and the center of the pivot portion, which is the fulcrum １ and the distance L between the center of the pressure applying part, which is the force point, and the center of the pivot part, which is the fulcrum. ２ Relative to L １ / L ２ The distance L between the center of the crimping portion and the center of the pivot portion in a crimping device for copper wire crimping. １ ' and the distance L between the center of the pressure applying portion and the center of the pivot portion ２ The ratio L １ ' / L ２ A pneumatic crimping device characterized by being smaller than '.

2. The distance L between the center of the crimping portion and the center of the pivot portion １ The distance L between the center of the crimping portion and the center of the pivot portion in a crimping device for copper wire crimping. １ 2. The pneumatic crimping device according to claim 1, wherein the length of the pneumatic crimping device is shorter than the length of the pneumatic crimping device.

3. The distance L between the center of the crimping portion and the center of the pivot portion １ and the distance L between the center of the pressure applying portion and the center of the pivot portion. ２ Relative to L １ / L ２ 2. The pneumatic crimping device according to claim 1, wherein is less than 0.

54.

4. 2. The pneumatic crimping device according to claim 1, further comprising a toggle mechanism having a slider to one end of which a driving force for the crimping operation is applied, and two links each having one end connected to the other end of the slider, wherein the other ends of the links of the toggle mechanism are connected to the pressure applying portions of the pair of crimping arms.

5. 5. The pneumatic crimping device according to claim 4, wherein the maximum angle formed by the two links of the toggle mechanism is larger than the maximum angle formed by the two links of a crimping device for crimping copper wires.

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