Tension adjusting device of kart transmission chain and control method

Abstract

The invention discloses a tension adjusting device of a kart transmission chain and a control method. The tensioning device comprises a first chain wheel (1) and a second chain wheel (2), a chain (3) is meshed on the first chain wheel (1) and the second chain wheel (2), a frame body (4) is arranged on the lower side of the chain (3), a third chain wheel (6) is rotationally arranged on the frame body (4), and the third chain wheel (6) is meshed with the lower side of the chain (3); a frame body (401) is arranged on the side portion of the frame body (4), and the chain (3) is arranged in the frame body (401) in a penetrating mode. A laser displacement sensor (402) and a photoelectric sensor (403) are arranged on the inner side of the frame body (401); and the lower part of the frame body (4) is connected with a lifting adjusting mechanism (5). The tensioning force can be adjusted according to the real-time running condition of the chain, the chain tensioning force can meet the power output requirement, and meanwhile the phenomena that the chain skips and the service life is shortened due to the fact that the chain tensioning force is too large are avoided.

Description

Technical Field

[0001] The invention relates to the technical field of kart accessories, in particular to a tension regulating device and a control method for a kart transmission chain. Background Art

[0002] Kart is a kind of sports, leisure and entertainment vehicle. Its transmission mode is similar to that of motorcycles, which uses chain transmission. When the kart runs at a high speed and for a long time, the chain is easy to loosen. The loose chain will reduce the transmission efficiency, aggravate wear, and even cause faults such as tooth jumping and chain flying, and increase the running noise. Therefore, a tensioning device is needed to tension the chain so that the chain maintains appropriate tension to ensure the stable operation of the transmission system and reduce energy loss and noise. For example, the Chinese utility model patent with the authorization announcement number CN200985996Y discloses a kart chain tensioner, which consists of a support arm, a chain guide wheel and a tension spring. The lower end of the support arm is connected with a tubular connecting sleeve, which is mounted on the mounting lug on the frame. The upper end of the support arm is equipped with a chain guide wheel, which is pressed on the chain. There is a tension spring hanging hole in the middle of the support arm, and the hook at one end of the tension spring is hung in the tension spring hanging hole of the support arm, and the hook at the other end is hung on the support lug of the frame. The utility model uses the tension spring installed between the support arm and the frame to keep the guide wheel pressed on the chain. The chain becomes longer during use, which can be compensated by the spring expansion and contraction of the tension spring, so that the tension force can be automatically adjusted in time; however, the utility model only presses the guide wheel on the chain through the tension spring. On the one hand, the tension of the tension spring gradually decreases after long-term use, and the force of the guide wheel pressing on the chain also gradually decreases, and it is difficult to ensure the tensioning effect for a long time; on the other hand, during the operation of the kart, the chain is affected by different vibrations and speeds, and the chain's demand for tension force will change. It is difficult to accurately regulate the change of tension force only through the tension spring. Summary of the invention

[0003] The purpose of the present invention is to provide a tension adjustment device and control method for a kart transmission chain. The present invention can adjust the tension according to the real-time operation of the chain, and can make the chain tension meet the power output requirements while avoiding excessive chain tension, which may lead to chain tooth skipping and shortened service life.

[0004] The technical solution of the present invention is as follows: a tensioning and adjusting device for a kart transmission chain comprises a mounting base fixed on the kart and located below the chain, a lifting and lowering adjustment mechanism is arranged on the mounting base, a frame is arranged at the lifting end of the lifting and lowering adjustment mechanism, a third sprocket is rotatably arranged on the frame, and the third sprocket is meshed with the outer side of the chain; a frame is arranged on the side of the frame, laser displacement sensors are respectively arranged on the upper and lower sides of the frame, photoelectric sensors are respectively arranged on the left and right sides of the frame, and the chain is passed through a cavity enclosed by the laser displacement sensor and the photoelectric sensor.

[0005] The above-mentioned tensioning device, the lifting and lowering adjustment mechanism includes a servo motor fixed on a mounting base, the moving end of the servo motor is connected to a screw rod, the outer side of the screw rod is meshed with a plurality of rollers, and the outer side of the rollers is meshed with roller nuts.

[0006] In the aforementioned tensioning device, a plurality of annular groove shoulders are provided on the inner side wall of the roller nut; a large diameter section and a small diameter section are provided at intervals on the roller; the small diameter section is meshed with the annular groove shoulder; and the large diameter section is meshed with the screw rod.

[0007] In the aforementioned tensioning device, the thread helix angles of the roller and the roller nut are both zero.

[0008] In the aforementioned tensioning device, a signal acquisition and processing module and a control module are provided on the side of the mounting base; the signal acquisition and processing module is respectively connected to the laser displacement sensor, the photoelectric sensor and the control module; and the control module is connected to the lifting and adjusting mechanism.

[0009] The aforementioned kart transmission chain tensioning adjustment device and control method, the control method comprises the following steps:

[0010] Step 1: Use a laser displacement sensor to collect the vibration displacement signal of the chain, and use a photoelectric sensor to collect the movement speed signal of the chain;

[0011] Step 2: Perform fast Fourier transform on the vibration displacement signal to obtain the displacement frequency, filter the displacement frequency and filter out the forced vibration frequency, retain the free vibration frequency, and obtain the vibration displacement of the chain; calculate the movement speed of the chain according to the movement speed signal;

[0012] Step 3: Calculate the tension of the chain according to the vibration displacement and movement speed;

[0013] Step 4: According to the size of the tensioning force, the lifting and lowering of the third sprocket is adjusted by controlling the lifting and lowering adjustment mechanism to achieve chain tension adjustment control.

[0014] In the aforementioned control method, in step 2, the calculation formula for calculating the movement speed of the chain according to the movement speed signal is as follows:

[0015]

[0016] Where V is the movement speed; N is the number of times the photoelectric sensor is triggered in one measurement cycle; Δt is the total time taken for the photoelectric sensor to be triggered N times; and d is the spacing between adjacent rollers of the chain.

[0017] In the aforementioned control method, in step 3, the calculation formula for calculating the tension of the chain according to the vibration displacement and the movement speed is as follows:

[0018]

[0019] Wherein, T is the real-time tension of the chain; h is the vibration displacement; a1 and a2 represent the preset constant coefficients respectively.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. When the tensioning device of the present invention is in use, the laser displacement sensor is used to measure the vibration displacement of the chain, the photoelectric sensor is used to measure the movement speed of the chain, and the lifting and adjusting mechanism is used to adjust the height of the third sprocket to adjust the tension of the chain; in addition, the photoelectric sensor can also be used to detect the uniformity of the chain gap. When the uniformity of the chain gap exceeds %, the standard for chain replacement is met; the present invention can obtain the corresponding relationship between the vibration displacement and movement speed of the chain and the tension in real time, and can accurately and dynamically adjust the chain tension through a servo motor according to the real-time situation of the chain operation, so that the chain tension can meet the power output demand while avoiding excessive chain tension that causes chain tooth jumping and shortening of life, effectively reducing the vibration aggravation, wear aggravation and energy efficiency loss caused by chain relaxation or excessive tension, and improving the stability, durability and operation efficiency of the kart chain transmission system.

[0022] 2. The inner wall of the roller nut of the present invention is provided with a plurality of annular groove shoulders; the roller is provided with a large diameter section and a small diameter section at intervals; the small diameter section is meshed with the annular groove shoulder; the large diameter section is meshed with the screw rod; the design of the roller and roller nut enables the roller to be precisely meshed with the roller nut and the screw rod, and has the advantages of compact structure, high load capacity, small guide force, sensitive response and rapid adjustment, adaptability to adverse conditions, low wear and good durability, high efficiency and low power loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the present invention;

[0024] Figure 2 It is a schematic diagram of the structure of the roller and the roller nut;

[0025] Figure 3 It is a structural block diagram of the control module of the present invention.

[0026] The marks in the accompanying drawings are: 1-first sprocket, 2-second sprocket, 3-chain, 4-frame, 401-frame, 402-laser displacement sensor, 403-photoelectric sensor, 5-lifting adjustment mechanism, 501-servo motor, 502-screw, 503-roller, 504-roller nut, 505-annular groove shoulder, 506-large diameter section, 507-small diameter section, 6-third sprocket, 7-mounting base, 8-screw electric cylinder. DETAILED DESCRIPTION

[0027] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the present invention.

[0028] Embodiment 1: A tensioning and adjusting device for a kart transmission chain, the structure of which is as follows: Figure 1 As shown, it includes a mounting base 7 fixed on the kart and located below the chain 3, and a lifting adjustment mechanism 5 for adjusting the height of the third sprocket 6 is arranged on the mounting base 7, and a frame 4 with a side shape of a right triangle is arranged at the lifting end of the lifting adjustment mechanism 5, and a third sprocket 6 is rotatably arranged on the frame 4, and the third sprocket 6 is meshed with the outer side of the chain 3, and the third sprocket 6 is connected to the idler wheel of the kart; the chain 3 is meshed with the first sprocket 1 and the second sprocket 2 respectively, the first sprocket 1 is connected to the kart driving motor, and the second sprocket 2 is connected to the driven wheel of the kart, and the diameter of the first sprocket 1 is smaller than the diameter of the second sprocket 2. A rectangular frame 401 is provided on the side of the frame 4; laser displacement sensors 402 for measuring the up and down vibration displacement of the chain 3 are respectively provided on the upper and lower sides of the frame 401, and photoelectric sensors 403 for measuring the movement speed of the chain 3 are respectively provided on the left and right sides of the frame 401. The chain 3 is inserted into the cavity enclosed by the laser displacement sensor 402 and the photoelectric sensor 403.

[0029] Lifting adjustment mechanism 5 Figure 2As shown, the lifting and lowering adjustment mechanism 5 includes a servo motor 501 fixed on the mounting base 7, and the moving end of the servo motor 501 is connected to a lead screw electric cylinder 8, which has the advantages of high transmission accuracy and large load-bearing capacity. The lead screw electric cylinder 8 includes a lead screw 502 connected to the moving end of the servo motor 501, and the outer side of the lead screw 502 is evenly distributed circumferentially and meshed with six rollers 503, and the rollers 503 are of multi-stage design. Three large-diameter sections 506 and four small-diameter sections 507 are evenly spaced on the rollers 503, and threads are provided on the large-diameter sections 506 and the small-diameter sections 507; the outer side of the roller 503 is meshed with a roller nut 504. The inner wall of the roller nut 504 is provided with four annular groove shoulders 505, and three annular grooves are formed between the annular groove shoulders 505. The annular groove shoulders 505 are provided with threads, while the annular grooves are not provided with threads; the small diameter section 507 is meshed with the annular groove shoulders 505; the large diameter section 506 is meshed with the screw 502, and the large diameter section 506 is accommodated in the annular groove. The roller 503 and the roller nut 504 of the present invention eliminate the setting of the roller end teeth and the inner gear ring in the traditional planetary roller screw electric cylinder, and the roller 503 of the present invention adopts a multi-stage segmented structure. The thread helix angles of the roller 503 and the roller nut 504 are both zero. Therefore, under the drive of the screw 502, there is no relative displacement between the roller 503 and the roller nut 504, but they move synchronously along the axial direction of the screw 502. The design of the roller 503 and the roller nut 504 enables the roller 503 to precisely mesh with the roller nut 504 and the screw 502, and has the advantages of compact structure, high load capacity, small guide force, sensitive response and rapid adjustment, adaptability to adverse conditions, low wear and good durability, high efficiency and low power loss.

[0030] The side of the mounting base 7 is provided with a signal acquisition processing module and a control module. The signal acquisition processing module is used to collect the vibration displacement signal and movement speed signal of the chain 3 collected by the laser displacement sensor 402 and the photoelectric sensor 403; the signal acquisition processing module is connected to the laser displacement sensor 402, the photoelectric sensor 403 and the control module respectively, and the signal acquisition processing module processes the vibration displacement signal and the movement speed signal to calculate the vibration displacement and movement speed of the chain 3, and then the signal acquisition processing module transmits the vibration displacement and movement speed to the control module; the photoelectric sensor 403 has higher accuracy, better environmental adaptability, wider measurement range, and is easy to fuse data with the laser displacement sensor 402 compared with the Hall sensor. The control module is connected to the lifting and adjusting mechanism 5, and the control module controls the servo motor 501 of the lifting and adjusting mechanism 5 to move, and the movement of the servo motor 501 drives the screw rod 502 to rotate, and the rotation of the screw rod 502 drives the moving end of the screw rod electric cylinder 8 to quickly adjust the height, and finally drives the third sprocket 6 to move up and down, so as to adjust the tension of the chain 3.

[0031] Working principle: When the tensioning device of the present invention is used, the laser displacement sensor 402 is used to measure the vibration displacement of the chain 3, the photoelectric sensor 403 is used to measure the movement speed of the chain 3, and the lifting adjustment mechanism 5 is used to adjust the height of the third sprocket 6 to adjust the tension of the chain 3; the roller 503 of the screw electric cylinder 8 adopts a multi-stage segmented structure. Under the drive of the screw 502, there is no relative displacement between the roller 503 and the roller nut 504, but they move synchronously along the axial direction of the screw 502; the design of the roller 503 and the roller nut 504 enables the roller 503 to accurately mesh with the roller nut 504 and the screw 502, and has the advantages of compact structure, high load capacity, small lead, sensitive response, fast adjustment, adaptability to adverse conditions, low wear and good durability, high efficiency and low power loss. In addition, the uniformity of the gap of the chain 3 can also be detected by the photoelectric sensor 403. When the uniformity of the gap of the chain 3 exceeds 1%, the standard for replacing the chain 3 is reached. The present invention can obtain the corresponding relationship between the vibration displacement and movement speed of the chain 3 and the tensioning force in real time, and can accurately and dynamically adjust the tensioning force of the chain 3 through the servo motor 501 according to the real-time operation situation of the chain 3, so that the tensioning force of the chain 3 can meet the power output demand while avoiding excessive tensioning force of the chain 3 that causes the chain 3 to jump teeth and shorten its life, effectively reducing the vibration aggravation, aggravated wear and energy efficiency loss caused by loose or over-tensioned chain 3, and improving the stability, durability and operation efficiency of the kart chain transmission system.

[0032] Embodiment 2: This embodiment provides a control method for chain adjustment based on the tension adjustment device of the kart transmission chain in Embodiment 1, comprising the following steps:

[0033] Step 1: Use a laser displacement sensor to collect the vibration displacement signal of the chain, use a photoelectric sensor to collect the movement speed signal of the chain, and transmit the vibration displacement signal and movement speed signal to the signal acquisition and processing module respectively.

[0034] Step 2: The signal acquisition and processing module performs fast Fourier transform processing on the vibration displacement signal to obtain the displacement frequency, performs filtering processing on the displacement frequency and filters out the forced vibration frequency, retains the free vibration frequency, and obtains the vibration displacement of the chain; the movement speed of the chain is calculated according to the movement speed signal;

[0035] In step 2, the calculation formula for calculating the movement speed of the chain 3 according to the movement speed signal is as follows:

[0036]

[0037] Wherein, V is the movement speed; N is the number of times the photoelectric sensor is triggered in one measurement cycle; Δt is the total time taken for the photoelectric sensor to be triggered N times, in seconds; and d is the spacing between adjacent rollers of the chain, in meters.

[0038] Step 3: Calculate the tension of the chain according to the vibration displacement and movement speed;

[0039] In step 3, the calculation formula for calculating the tension of the chain based on the vibration displacement and movement speed is as follows:

[0040]

[0041] Among them, T is the real-time tension of the chain; h is the vibration displacement; a1 and a2 represent the preset constant coefficients, and their values ​​are set according to the on-site experimental calibration based on the vehicle dynamic performance and chain parameters of the kart. Since the tension required by the chain is related to the vibration displacement and movement speed, when the movement speed of the chain increases, due to the inertia effect, a greater tension is required to maintain the movement state of the chain, thereby ensuring the continuity and efficiency of the transmission; on the contrary, if the speed decreases, the tension required by the chain will also decrease accordingly.

[0042] Step 4: The control module adjusts the lifting and lowering of the third sprocket by controlling the lifting and lowering adjustment mechanism according to the size of the tensioning force, thereby realizing the tensioning force adjustment control of the chain.

[0043] In summary, the present invention can obtain the corresponding relationship between the vibration displacement and movement speed of the chain and the tensioning force in real time, and can accurately and dynamically adjust the chain tensioning force through the lifting and lowering adjustment mechanism according to the real-time situation of the chain operation, so that the chain tensioning force can meet the power output demand while avoiding excessive chain tensioning that leads to chain tooth jumping and shortening of life, effectively reducing the increased vibration, increased wear and energy efficiency loss caused by chain relaxation or excessive tensioning, and improving the stability, durability and operation efficiency of the kart chain transmission system.

[0044] The above embodiments only express the implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. In this embodiment, the words "up", "down", "left", "right", "front" and "rear" only represent their relative positions and do not represent their absolute positions. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A tensioning and adjusting device for a kart transmission chain, characterized in that: The invention comprises a mounting base (7) fixed on a go-kart and located below a chain (3); a lifting adjustment mechanism (5) is arranged on the mounting base (7); a frame (4) is arranged at the lifting end of the lifting adjustment mechanism (5); a third sprocket (6) is rotatably arranged on the frame (4); the third sprocket (6) is meshed with the outer side of the chain (3); a frame (401) is arranged on the side of the frame (4); laser displacement sensors (402) are arranged on the upper and lower sides of the frame (401); photoelectric sensors (403) are arranged on the left and right sides of the frame (401); and the chain (3) is inserted into a cavity enclosed by the laser displacement sensor (402) and the photoelectric sensor (403).

2. The kart transmission chain tensioning and adjusting device according to claim 1, characterized in that: The lifting and lowering adjustment mechanism (5) comprises a servo motor (501) fixed on a mounting base (7); a moving end of the servo motor (501) is connected to a screw rod (502); a plurality of rollers (503) are meshed on the outer side of the screw rod (502); and a roller nut (504) is meshed on the outer side of the roller (503).

3. The kart transmission chain tensioning and adjusting device according to claim 2, characterized in that: The inner side wall of the roller nut (504) is provided with a plurality of annular groove shoulders (505); the roller (503) is provided with large diameter sections (506) and small diameter sections (507) at intervals; the small diameter section (507) is meshed with the annular groove shoulders (505); and the large diameter section (506) is meshed with the screw rod (502).

4. The kart transmission chain tensioning and adjusting device according to claim 3, characterized in that: The thread helix angles of the roller (503) and the roller nut (504) are both zero.

5. The kart transmission chain tensioning and adjusting device according to claim 1, characterized in that: A signal acquisition and processing module and a control module are provided on the side of the mounting base (7); the signal acquisition and processing module is respectively connected to the laser displacement sensor (402), the photoelectric sensor (403) and the control module; and the control module is connected to the lifting and lowering adjustment mechanism (5).

6. The control method of the tensioning adjustment device of the kart transmission chain according to any one of claims 1 to 5, characterized in that: The control method comprises the following steps: Step 1: Use a laser displacement sensor to collect the vibration displacement signal of the chain, and use a photoelectric sensor to collect the movement speed signal of the chain; Step 2: Perform fast Fourier transform on the vibration displacement signal to obtain the displacement frequency, filter the displacement frequency and filter out the forced vibration frequency, retain the free vibration frequency, and obtain the vibration displacement of the chain; calculate the movement speed of the chain according to the movement speed signal; Step 3: Calculate the tension of the chain according to the vibration displacement and movement speed; Step 4: According to the size of the tensioning force, the lifting and lowering of the third sprocket is adjusted by controlling the lifting and lowering adjustment mechanism to achieve chain tension adjustment control.

7. The control method according to claim 6, characterized in that: In step 2, the calculation formula for calculating the movement speed of the chain according to the movement speed signal is as follows: Where V is the movement speed; N is the number of times the photoelectric sensor is triggered in one measurement cycle; Δt is the total time taken for the photoelectric sensor to be triggered N times; and d is the spacing between adjacent rollers of the chain.

8. The control method according to claim 6, characterized in that: In step 3, the calculation formula for calculating the tension of the chain based on the vibration displacement and movement speed is as follows: Wherein, T is the real-time tension of the chain; h is the vibration displacement; a1 and a2 represent the preset constant coefficients respectively.

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