CN115743328A

CN115743328A - Transmission mechanism and stepless-regulation electric tail wing with same

Info

Publication number: CN115743328A
Application number: CN202211523625.7A
Authority: CN
Inventors: 黄森荣; 李书亮
Original assignee: Ningbo Huakai Electronic Technology Co ltd
Current assignee: Ningbo Huakai Electronic Technology Co ltd
Priority date: 2022-11-30
Filing date: 2022-11-30
Publication date: 2023-03-07

Abstract

The invention relates to a transmission mechanism and an electrodeless adjusting electric tail wing with the same, wherein the transmission mechanism comprises an input screw rod and an output screw rod which are arranged in parallel, and a transmission nut used for connecting the input screw rod and the output screw rod; also comprises a tail wing body; the driving mechanism is positioned in the middle of the tail wing body and is in transmission fit with the transmission mechanism; at least 2 transmission mechanisms are symmetrically arranged on two sides of the driving mechanism; the tail wing adjusting mechanism is positioned on the outermost side of the tail wing body and is driven by the transmission mechanism to adjust the height and the angle of the tail wing body. The invention has the beneficial effects that: the double-screw rod is driven in an electrodeless way: the whole power transmission shaft is not subjected to direction change, so that the assembly precision is better controlled; the self-locking and stepless control functions are realized through the screw nut structure, compared with a worm gear or gear structure, the noise can be effectively reduced, and the operation is more stable.

Description

Transmission mechanism and stepless-regulation electric tail wing with same

Technical Field

The invention relates to the technical field of automobile parts, in particular to a transmission mechanism and a stepless-regulation electric empennage with the same.

Background

The automobile tail fin is called as a spoiler in a professional name, and belongs to a part of an automobile aerodynamic kit. The automobile tail fin mainly has the effect of reducing the lift force of the tail of a vehicle, and if the lift force of the tail of the vehicle is larger than that of the head of the vehicle, the oversteer of the vehicle, the reduction of the ground holding force of rear wheels and the deterioration of high-speed stability are easily caused.

The working principle is as follows: when the automobile runs at high speed, according to the aerodynamic principle, air resistance can be met in the running process, air power in the longitudinal direction, the lateral direction and the vertical rising direction is generated around the gravity center of the automobile simultaneously, and the longitudinal direction is the air resistance. In order to effectively reduce and overcome the influence of air resistance when an automobile runs at high speed, the automobile tail fin is designed and used, and has the function of enabling air to generate a fourth acting force on the automobile, namely generating larger adhesive force on the ground, and the automobile tail fin can counteract a part of lifting force, effectively control the automobile to float upwards, enable the wind resistance coefficient to be correspondingly reduced, enable the automobile to closely cling to the road ground to run, and further improve the running stability.

The automobile tail fin has the effects that when an automobile runs at a high speed, air resistance forms downward pressure, lift force is counteracted as much as possible, the downward pressure of airflow is effectively controlled, the wind resistance coefficient is correspondingly reduced, and the high-speed running stability of the automobile is improved; because the empennage can reduce the air resistance of the automobile, the installation of the empennage on the high-speed automobile also has certain help to save fuel; meanwhile, the appearance of the automobile is more attractive, and a certain decorative effect is achieved.

Some foreign people figuratively call it a "ski" according to its shape. The duck tail or the wind-stabilizing wing is also called in China, and the more scientific name is 'spoiler', 'spoiler wing' or 'spoiler'. The empennage is generally divided into a single-layer empennage and a double-layer empennage, the empennage is made of aluminum alloy empennage and carbon fiber, and the empennage is divided into manual adjustment and hydraulic automatic adjustment, wherein the hydraulic automatic adjustment is provided with a plurality of hydraulic upright posts, and the angle can be automatically adjusted according to the vehicle speed.

The improvement of the empennage is an electric empennage produced under the leading technology, the electric empennage receives a speed signal by a computer board, quickly leads out air turbulence at high speed, receives the speed signal by the computer board, further changes the angle and the height of the empennage, and increases the downward pressure of the tail part to ensure the driving stability of the vehicle at high speed; during high-speed running, the angle of the tail wing is automatically adjusted through braking and emergency braking, and the functions of assisting braking and balancing the vehicle body are achieved.

However, the existing electric empennage has certain defects, such as: 1. the synchronization is poor, because two motor driving systems are adopted for operation, the synchronization rate of the movement mechanisms on the two sides is controlled by electrons and software, and the synchronization at the two ends of the tail wing is poor, the running is dangerous when the single side collapses and fails; 2. the opening position is single, and the opening positions of most products are only two or three, or fixed. The selection range of the opening angle is single (and a large amount of angle calibration, development and manufacturing control processes are generated); 3. the transmission system has low reliability and safety of the mechanism, the transmission part is mostly driven by screw nuts, gaps between transmission fit of the mechanism are not eliminated, the operation is not stable and noise is generated.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides a transmission mechanism.

A transmission mechanism comprises an input lead screw, an output lead screw and a transmission nut, wherein the input lead screw and the output lead screw are arranged in parallel;

and the transmission nut is provided with an input hole and an output hole which are matched with the input lead screw and the output lead screw.

The technical scheme is further set as follows: the input lead screw is a single-head small-lead self-locking lead screw, and the output lead screw is a multi-head large-lead non-self-locking lead screw.

The invention also provides a stepless regulation electric empennage.

A stepless regulation electric empennage comprises a tail body,

a tail body;

the driving mechanism is positioned in the middle of the tail wing body and is in transmission fit with the transmission mechanism;

at least 2 transmission mechanisms as claimed in claim 1 or 2, and symmetrically arranged at two sides of the driving mechanism;

the method is characterized in that: the tail wing adjusting mechanism is positioned on the outermost side of the tail wing body and is driven by the transmission mechanism to adjust the height and the angle of the tail wing body;

an output shaft is arranged on the driving mechanism, and the output shaft and the input screw rod are coaxially arranged; the input lead screw is in transmission connection with the output shaft;

the output screw is provided with a driving shaft, and the transmission mechanism is in transmission connection with the tail wing adjusting mechanism through the driving shaft.

The technical scheme is further set as follows: the driving mechanism is sequentially connected with a motor, a speed reducer and an output gear set according to a transmission sequence, the output shaft is positioned on the output gear set, and the motor and the output shaft are arranged side by side and are transversely arranged;

the input lead screw and the output shaft form synchronous transmission fit through a synchronous shaft sleeve.

The technical scheme is further set as follows: the tail wing adjusting mechanism comprises a multi-connecting-rod hinge group and a connecting sheet fixed with the tail wing body; the multi-connecting-rod hinge group is provided with an adjusting sleeve, and the connecting piece is driven by a plurality of adjusting sleeves to move.

The technical scheme is further set as follows: the multi-connecting-rod hinge group comprises an input connecting rod hinge, a first swing rod sleeve and a second swing rod sleeve which are arranged in a transmission sequence; wherein, the input end of the input connecting rod hinge is in transmission connection with the driving shaft; the adjusting sleeve is connected to the first swing rod sleeve and the second swing rod sleeve.

The technical scheme is further set as follows: the input connecting rod hinge comprises an input oscillating rod and an output oscillating rod, wherein the input oscillating rod is connected with the driving shaft and the output oscillating rod is connected with the input oscillating rod through a connecting rod pin; the output end of the output swing rod is connected with the first swing rod sleeve.

The technical scheme is further set as follows: the first swing rod sleeve comprises two first swing walls which are symmetrically arranged, and the upper ends of the two first swing walls are connected through a first supporting end face; the output end of the output swing rod is communicated with the first swing wall through a connecting rod pin;

the second swing rod sleeve comprises two second swing walls which are symmetrically arranged, and the upper ends of the two second swing walls are connected through a second supporting end face;

the first swing wall and the second swing wall are symmetrically arranged on two sides of the input connecting rod hinge.

The technical scheme is further set as follows: the driving shaft penetrates through the second swing wall and is connected with the input swing rod; and a bearing is arranged between the driving shaft and the second swinging wall.

The technical scheme is further set as follows: the output end of the first swing wall, the output end of the second swing wall and the adjusting sleeve are in transmission connection through connecting rod pins respectively.

The invention has the beneficial effects that:

1. the double-screw rod is driven in an electrodeless way: the whole power transmission shaft is not subjected to direction change, so that the assembly precision is better controlled; the self-locking and stepless control functions are realized through the screw nut structure, and compared with a worm gear or gear structure, the noise can be effectively reduced, and the operation is more stable;

2. stepless opening angle: the angle and the height of the connecting sheet are adjusted by adopting the multi-connecting-rod hinge group, different air stable pressures of the vehicle body are provided according to different vehicle speeds, a wide working range can be realized, and development and matching are easy;

3. the mechanism is compact: the motors and the output shafts are arranged side by side and are transversely arranged, and the double screw rods are arranged in parallel and are transversely arranged with the multi-connecting-rod hinge group, so that the overall layout is more compact and practical, and the operation is stable and reliable;

4. the middle driving connecting rod is arranged: the input connecting rod is hinged in the middle of the tail wing adjusting mechanism, so that the two swing rod sleeves are stressed more uniformly and stably; compared with the driving connecting rod arranged on the side face in a single-side mode, the single-side stress situation is avoided, the structure is compact, and the requirement on the arrangement space is small.

Drawings

Fig. 1 is a schematic structural diagram of a transmission mechanism.

Fig. 2 is a schematic diagram of an explosive structure of embodiment 1.

Fig. 3 is a schematic cross-sectional structure of embodiment 1.

Fig. 4 is a schematic structural view of embodiment 2.

Fig. 5 is an exploded view of embodiment 2.

Fig. 6 is an assembly diagram of the driving mechanism, the transmission mechanism and the tail adjusting mechanism in embodiment 2.

Fig. 7 is an exploded view of the transmission mechanism and the tail adjustment mechanism in embodiment 2.

Fig. 8 is an isometric cross-sectional view of a multi-link hinge set of embodiment 2.

Fig. 9 is a schematic structural view of a multi-link hinge group according to embodiment 2.

Fig. 10 is a schematic view of the installation structure of the multi-link hinge group and the connecting link in embodiment 2.

The attached drawings are marked with: 100. inputting a lead screw; 200. an output screw; 300. a drive nut; 301. an input aperture; 302. an output aperture; 400. a housing; 500. an end cap; 600. a seal ring; 700. a first bearing; 800. a shaft sleeve; 900. an oil seal ring;

10. a tail body; 20. a drive mechanism; 21. a motor; 22. a speed reducer; 23. an output gear set; 30. a transmission mechanism; 40. an empennage adjusting mechanism; 41. connecting sheets; 42. an adjusting sleeve; 43. an input link hinge; 44. a first swing rod sleeve; 45. a second swing rod sleeve; 431. inputting a swing rod; 432. an output swing rod; 441. a first swing wall; 442. a first support end face; 451. a second swing wall; 452. a second support end face; 46. a link pin; 47. a connecting rod base; 50. beautifying the board; 60. a fixing plate; 70. an output shaft; 80. a drive shaft; 90. synchronous axle sleeve.

Detailed Description

To further illustrate the technical means and effects of the present invention adopted to achieve the predetermined objects, the following detailed description of the embodiments, structures, features and effects according to the present invention will be made with reference to the accompanying drawings and preferred embodiments.

Example 1

Referring to fig. 1 to 3, a transmission mechanism includes an input lead screw 100 and an output lead screw 200 arranged in parallel, and a transmission nut 300 for connecting the input lead screw 100 and the output lead screw 200;

the transmission nut 300 is provided with an input hole 301 and an output hole 302 which are matched with the input lead screw 100 and the output lead screw 200.

Preferably, the input lead screw 100 is a single-head small-lead self-locking lead screw, and the output lead screw 200 is a multi-head large-lead non-self-locking lead screw.

In this embodiment, the input screw 100 and the output screw 200 are arranged in parallel, and the input screw 100 and the output screw 200 are drivingly connected by the drive nut 300. The input screw 100 is driven by the external driving mechanism 20 to rotate, the input screw 100 drives the transmission nut 300 to move back and forth when rotating, the transmission nut 300 is connected with the output screw 200, and the output screw 200 is driven to rotate so as to output torque. Because the input screw 100 is a self-locking screw, the input screw cannot be driven when reversely driven from the output screw 200, thereby realizing stepless control.

The whole power transmission shaft does not undergo direction change during arrangement, so that the assembly precision is better controlled; self-locking and electrodeless control function realize through screw nut structure, compare among the prior art can effective noise reduction through worm gear or gear structure, operate more steadily.

In this embodiment, a casing 400 with openings at two ends is further provided, an end cap 500 is provided at the opening of the casing 400, and the end cap 500 and the casing 400 are sealed by a sealing ring 600. The input screw 100 and the output screw 200 are connected to the end caps 500 at both ends, respectively, to perform stable transmission.

The method specifically comprises the following steps: the input end of the input screw 100 extends out of the end cover 500, and an oil seal ring 900 is arranged between the input end of the input screw and the end cover 500; the output end of the output screw 200 extends to the outside of the end cover 500, and an oil seal ring 900 is arranged between the output end and the end cover 500. Meanwhile, the two ends of the output screw 200 are connected to the end cap 500 via the first bearing 700, so that the output screw 200 can rotate freely. Both end portions of the input lead screw 100 are provided with bushings 800.

In this embodiment, the oil seal ring 900 is disposed at the shaft outlet of the two ends of the transmission mechanism 30, the seal ring 600 is disposed at the end cap 500 of the two ends, and the mechanism is self-sealed and can be disposed in an exposed environment.

Example 2

Referring to fig. 4 to 10, the present embodiment provides a stepless adjusting electric rear wing, including,

a tail body 10;

the driving mechanism 20 is positioned in the middle of the tail wing body 10 and forms transmission fit with the transmission mechanism 30;

at least 2 transmission mechanisms 30 described in embodiment 1, and symmetrically arranged on two sides of the driving mechanism 20;

the tail wing adjusting mechanism 40 is positioned at the outermost side of the tail wing body 10 and is driven by the transmission mechanism 30 to adjust the height and the angle of the tail wing body 10;

an output shaft 70 is arranged on the driving mechanism 20, and the output shaft 70 and the input lead screw 100 are coaxially arranged; the input lead screw 100 is in transmission connection with the output shaft 70;

the output screw 200 is provided with a driving shaft 80, and the transmission mechanism 30 is in transmission connection with the tail adjusting mechanism 40 through the driving shaft 80.

In the embodiment, the same set of driving mechanism 20 drives the transmission mechanisms 30 on two sides, which is superior to the structure of independently driving the transmission mechanisms 30 by the single-side motor 21 on the market, so that the risk of safety accidents caused by one-side collapse of the empennage body 10 and further side-tipping of the vehicle body due to single-side transmission failure is effectively avoided.

Specifically, the driving mechanism 20 is sequentially connected with a motor 21, a speed reducer 22 and an output gear set 23 according to a transmission sequence, the output shaft 70 is located on the output gear set 23, and the motor 21 and the output shaft 70 are arranged side by side and are both transversely arranged;

the input lead screw 100 and the output shaft 70 form synchronous transmission fit through a synchronous shaft sleeve 90800.

In some embodiments of the present invention, the tail adjusting mechanism 40 includes a multi-link hinge set, and a connecting piece 41 fixed to the tail body 10; the multi-connecting-rod hinge group is provided with an adjusting sleeve 42, and the connecting piece 41 is driven by the adjusting sleeve 42 to move.

The structural composition form of many connecting rods hinge group is various, provides a preferred scheme who is applicable to electronic fin in this embodiment, specifically does: the multi-link hinge group comprises an input link hinge 43, a first swing link sleeve 44 and a second swing link sleeve 45 which are arranged in a transmission sequence; wherein, the input end of the input connecting rod hinge 43 is in transmission connection with the driving shaft 80; the adjusting sleeve 42 is connected to the first pendulum sleeve 44 and the second pendulum sleeve 45.

The driving shaft 80 on the transmission mechanism 30 drives the input connection hinge to transmit, and the input link hinge 43 transmits the first swing rod sleeve 44 and the second swing rod sleeve 45 in the rotating process, so that the heights and the angles of the first swing rod sleeve 44 and the second swing rod sleeve 45 are changed, and the positions of the adjusting sleeves 42 arranged on the first swing rod sleeve 44 and the second swing rod sleeve 45 are changed, so that the height and the angle of the tail body 10 are changed.

Preferably, the input link hinge 43 includes an input swing link 431 connected to the driving shaft 80 and an output swing link 432 connected to the input swing link 431 through a link pin 46, which are arranged in series; the output end of the output swing link 432 is connected to the first swing link sleeve 44.

The first swing rod sleeve 44 comprises two first swing walls 441 which are symmetrically arranged, and the upper ends of the two first swing walls 441 are connected through a first supporting end surface 442; the output end of the output swing link 432 is connected with the first swing wall 441 through a link pin 46;

the second swing rod sleeve 45 comprises two symmetrically arranged second swing walls 451, and the upper ends of the two second swing walls 451 are connected through a second supporting end face 452;

the first swing wall 441 and the second swing wall 451 are symmetrically disposed on both sides of the input link hinge 43.

The two first swing walls 441 are connected into a whole through the first supporting end surface 442, the two second swing walls 451 are connected into a whole through the second supporting end surface 452, the downward pressure generated by the empennage body 10 is borne by the two first swing walls 441 and the two second swing walls 451 together, and the symmetrically formed structure enables the multi-link hinge group to operate more stably. Compared with a transmission unilateral single-connecting-rod structure, the symmetrical integrated connecting rod can bear larger pressure, more stably operates and has higher connecting rod strength.

Meanwhile, the input connecting rod hinge 43 is arranged between the first swing rod sleeve 44 and the second swing rod sleeve 45, so that the stress of the input connecting rod hinge 43 is more uniform and stable; compared with the unilateral arrangement mode of the side surface, the unilateral stress condition can not occur, the structure is compact, and the requirement on the arrangement space is small.

Furthermore, the first and second

support end surfaces

442 and 452 are provided to support the adjustment sleeve 42, so that the adjustment sleeve 42 is more stable when being pressed.

The drive shaft 80 is connected to the input pendulum 431 through the second pendulum wall 451; a second bearing is arranged between the drive shaft 80 and the second pendulum wall 451.

When the driving shaft 80 rotates, due to the arrangement of the second bearing, the second swing wall 451 does not rotate relative to the driving shaft 80, that is, the second swing link sleeve 45 does not move, the driving shaft 80 transmits torque to the input swing link 431, so that the input swing link 431 rotates, and the input swing link 431 drives the output swing link 432 to rotate in the rotating process. The input end of the input swing link 431 is connected to the drive shaft 80 so that the output end rotates about the input end. The input end of the output swing link 432 is connected to the output end of the input swing link 431, so that the input end of the output swing link 432 also rotates around the input end of the input swing link 431, and the output end of the output swing link 432 swings.

The output end of the first swing wall 441 and the output end of the second swing wall 451 are in transmission connection with the adjusting sleeve 42 through a connecting rod pin 46.

The output end of the output swing link 432 is connected to the first swing link sleeve 44, so as to drive the first swing link sleeve 44 to swing.

The first rocker sleeve 44 is connected to the adjustment sleeve 42 by a link pin 46, which causes the adjustment sleeve 42 to pivot. Meanwhile, the second swing link cover 45 and the adjustment cover 42 are connected by the link pin 46, and thus the second swing link cover 45 is also swung together.

In this embodiment, a connecting rod base 47 is further provided, an input end of the second swing rod sleeve 45 is connected to the connecting rod base 47, and meanwhile, an end of the first swing rod sleeve 44 is also connected to the connecting rod base 47 through a connecting rod pin 46, so that swing positions of the first connecting rod sleeve and the second connecting rod sleeve are limited. Meanwhile, the ends of the first link sleeve and the second link sleeve connected with the link base 47 are both located opposite to the end connected with the adjusting sleeve 42.

In order to better protect each part and make the electric empennage more beautiful, the electric empennage also comprises a beautifying plate 50 and a fixed bottom plate, wherein the beautifying plate 50 is fixed on the lower end surface of the empennage body 10, a hollow part is arranged at the position of the empennage adjusting mechanism 40, and the empennage adjusting mechanism 40 is fixed with the empennage body 10 through the hollow part; the fixing plate 60 is disposed under the beautification plate 50 and fixed to the lower end of the tail adjustment mechanism 40, and an installation space is formed between the beautification plate 50 and the fixing plate 60, and the driving mechanism 20, the transmission mechanism 30, and the tail adjustment mechanism 40 are located in the installation space.

The electric empennage is fixed with the automobile body through the fixing plate 60, the fixing plate 60 is provided with a welding nut or an insert nut, a waterproof pad is arranged, and water is placed to enter the automobile body from the screw.

Although the present invention has been described with reference to the preferred embodiments, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A transmission mechanism is characterized in that: the device comprises an input lead screw (100) and an output lead screw (200) which are arranged in parallel, and a transmission nut (300) used for connecting the input lead screw (100) and the output lead screw (200);

and the transmission nut (300) is provided with an input hole (301) and an output hole (302) which are matched with the input lead screw (100) and the output lead screw (200).

2. The transmission mechanism as claimed in claim 1, wherein: the input lead screw (100) is a single-head small-lead self-locking lead screw, and the output lead screw (200) is a multi-head large-lead non-self-locking lead screw.

3. A stepless regulation electric empennage comprises a tail,

a tail body (10);

the driving mechanism (20) is positioned in the middle of the tail wing body (10) and forms transmission fit with the transmission mechanism (30);

-at least 2 transmission mechanisms (30) according to claim 1 or 2, symmetrically arranged on both sides of the driving mechanism (20);

the method is characterized in that: the tail wing adjusting mechanism (40) is positioned at the outermost side of the tail wing body (10) and is driven by the transmission mechanism (30) to adjust the height and the angle of the tail wing body (10);

an output shaft (70) is arranged on the driving mechanism (20), and the output shaft (70) and the input lead screw (100) are coaxially arranged; the input lead screw (100) is in transmission connection with the output shaft (70);

the output screw rod (200) is provided with a driving shaft (80), and the transmission mechanism (30) is in transmission connection with the tail wing adjusting mechanism (40) through the driving shaft (80).

4. Stepless regulation electric tail according to claim 3, characterized in that: the driving mechanism (20) is sequentially connected with a motor (21), a speed reducer (22) and an output gear set (23) according to a transmission sequence, the output shaft (70) is positioned on the output gear set (23), and the motor (21) and the output shaft (70) are arranged side by side and are transversely arranged;

the input lead screw (100) and the output shaft (70) form synchronous transmission matching through synchronous shaft sleeves (90) (800).

5. Stepless regulation electric tail according to claim 3, characterized in that: the tail wing adjusting mechanism (40) comprises a multi-connecting-rod hinge group and a connecting sheet (41) fixed with the tail wing body (10); the multi-connecting-rod hinge group is provided with an adjusting sleeve (42), and the connecting piece (41) is driven by the adjusting sleeve (42) to move.

6. Stepless regulation electric tail according to claim 5, characterized in that: the multi-connecting-rod hinge group comprises an input connecting rod hinge (43), a first swing rod sleeve (44) and a second swing rod sleeve (45) which are arranged in a transmission sequence; wherein the input end of the input connecting rod hinge (43) is in transmission connection with the driving shaft (80); the adjusting sleeve (42) is connected to the first swing rod sleeve (44) and the second swing rod sleeve (45).

7. Stepless regulation electric tail according to claim 6, characterized in that: the input connecting rod hinge (43) comprises an input swing rod (431) and an output swing rod (432), wherein the input swing rod (431) is connected with the driving shaft (80) and the output swing rod (432) is connected with the input swing rod (431) through a connecting rod pin (46); the output end of the output swing rod (432) is connected with the first swing rod sleeve (44).

8. Stepless regulation electric tail according to claim 6, characterized in that: the first swing rod sleeve (44) comprises two first swing walls (441) which are symmetrically arranged, and the upper ends of the two first swing walls (441) are connected through a first supporting end surface (442); the output end of the output swing rod (432) is connected with the first swing wall (441) through a connecting rod pin (46);

the second swing rod sleeve (45) comprises two second swing walls (451) which are symmetrically arranged, and the upper ends of the two second swing walls (451) are connected through a second supporting end surface (452);

the first swing wall (441) and the second swing wall (451) are symmetrically arranged on two sides of the input link hinge (43).

9. Stepless regulation electric tail according to claim 8, characterized in that: the driving shaft (80) passes through the second swing wall (451) and is connected with an input swing rod (431); a bearing is arranged between the drive shaft (80) and the second swing wall (451).

10. Stepless regulation electric tail according to claim 8, characterized in that: the output end of the first swing wall (441) and the output end of the second swing wall (451) are in transmission connection with the adjusting sleeve (42) through connecting rod pins (46).