CN111063249B

CN111063249B - Table tennis universal shaft demonstration instrument

Info

Publication number: CN111063249B
Application number: CN201911339652.7A
Authority: CN
Inventors: 张兴海
Original assignee: Yanshan University
Current assignee: Yanshan University
Priority date: 2019-12-23
Filing date: 2019-12-23
Publication date: 2021-09-14
Anticipated expiration: 2039-12-23
Also published as: CN111063249A

Abstract

The invention discloses a table tennis universal shaft demonstration instrument, which belongs to the field of sports goods and comprises a base and vertical rods fixed on the base, wherein the lower parts of the vertical rods are hinged with shaft sleeves, the top ends of the vertical rods are fixedly connected with ball cage universal joints, main shafts of the ball cage universal joints are connected with universal rods, and balls are hinged on the universal rods; the utility model discloses a bearing, including axle sleeve, axle sleeve both sides are provided with two horizontal poles, and the axle sleeve rear end is provided with horizontal back branch, and the axle sleeve front end is provided with horizontal front strut, and the contained angle is 90 between adjacent horizontal pole, horizontal back branch, the horizontal front strut. The invention can demonstrate the rotation condition of the ball body according to a plurality of direction axes respectively, so that students can visually see the flying direction of the table tennis and the phenomenon that the ball body rotates according to different direction axes, and the students can understand the technical theory of the table tennis rotation axis.

Description

Table tennis universal shaft demonstration instrument

Technical Field

The invention relates to the field of sports goods, in particular to a table tennis universal shaft demonstration instrument used in the theoretical teaching of table tennis technology.

Background

The basic theory of rotation axis and rotation property of table tennis is mainly as follows: the table tennis ball is an object without a fixed shaft, but under the action of external force, a rotating shaft is necessarily generated when the table tennis ball rotates. Because the table tennis can rotate in any direction during flying, the rotating shaft of the table tennis is infinite; in the course of teaching the technical theory of table tennis, in order to make students understand the rotation and flight rules of table tennis more quickly and better, demonstration instruments are often used for assisting teaching. The applicant previously developed a table tennis strength and strength rotation change demonstration instrument (201420368781.5), a table tennis coordinate axis demonstration instrument (201120251509.5) and a table tennis rotation axis experiment demonstration instrument (200720138431. X). The three demonstration instruments play a good auxiliary role in teaching and training the table tennis technical theory, and practice proves that the three demonstration instruments can assist athletes in quickly understanding and mastering the table tennis technical theory knowledge. However, in the practical application process, it is found that although the table tennis strength and rotation change and coordinate axis demonstration instrument can demonstrate the table tennis rotation axis, the table tennis strength and rotation change and coordinate axis demonstration instrument is only limited to demonstrate the rotation phenomenon of the ball body along the left and right axes, the upper and lower axes and the front and rear axes, and the table tennis rotation along the mixed axis (also called deflection axis) of the three basic rotation axes cannot be demonstrated. Although the table tennis rotating shaft experiment demonstration instrument can demonstrate the process that the table tennis rotates along different directions, the comparison conditions of the mixing shaft and the left and right shafts, the upper and lower shafts, the front and rear shafts and the deflection degree of the mixing shaft cannot be demonstrated.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a table tennis cardan shaft demonstration instrument, which can demonstrate the rotation condition of a ball body according to a plurality of direction shafts respectively, so that students can visually see the flying direction of the table tennis and the phenomenon that the ball body rotates according to different direction shafts, and the students can understand the technical theory of the table tennis rotation shaft.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

the table tennis universal shaft demonstration instrument comprises a base and a vertical rod fixed on the base, wherein the lower part of the vertical rod is hinged with a shaft sleeve, the top end of the vertical rod is fixedly connected with a ball cage universal joint, a main shaft of the ball cage universal joint is connected with a universal rod, and a ball body is hinged on the universal rod; the utility model discloses a bearing, including axle sleeve, axle sleeve both sides are provided with two horizontal poles, and the axle sleeve rear end is provided with horizontal back branch, and the axle sleeve front end is provided with horizontal front strut, and the contained angle is 90 between adjacent horizontal pole, horizontal back branch, the horizontal front strut.

The technical scheme of the invention is further improved as follows: the base comprises an L plate at the bottom end, a horizontal bottom plate is fixed on the L plate, a frustum-shaped bottom support is fixed on the bottom plate, the lower end of the vertical rod is fixedly and vertically connected with the center of the upper end of the bottom support, and a fastening bolt is arranged on the L plate.

The technical scheme of the invention is further improved as follows: cup joint a circular shape circle frame on two horizontal poles, horizontal back branch, the horizontal front strut, two horizontal poles, horizontal back strut tip and the inboard fixed connection of circle frame, horizontal front strut passes and continues to extend forward behind the circle frame, and is fixed with the arrow point at horizontal front strut front end, establishes the scale mark on the circle frame.

The technical scheme of the invention is further improved as follows: the shaft sleeve is internally provided with a central hole, two ends of the central hole of the shaft sleeve are hinged with the vertical rod through a large bearing, and the upper end and the lower end of the shaft sleeve are fastened with the vertical rod through fastening nuts.

The technical scheme of the invention is further improved as follows: the ball body is provided with a central through hole, two ends of the central through hole of the ball body are hinged with the universal rod through the small bearing, and two ends of the central through hole of the ball body are provided with fastening nuts.

Due to the adoption of the technical scheme, the invention has the technical progress that:

the table tennis universal shaft demonstration instrument has simple structure and convenient use. The demonstration instrument is provided with the ball cage universal joint and the universal rod, can demonstrate the rotation condition of the ball body according to a plurality of direction shafts respectively, can adjust the ball body to rotate along a left shaft, a right shaft, an upper shaft, a lower shaft, a front shaft and a rear shaft, and can adjust the ball body to rotate along an inclined shaft. The student can visually see the flying direction of the table tennis and the rotation of the ball body according to different direction axes. Therefore, students are helped to understand the technical theory of the table tennis rotating shaft; the horizontal front supporting rod of the demonstration instrument is provided with an arrow so as to conveniently indicate the motion direction of table tennis balls, the front supporting rod, the rear supporting rod, the horizontal cross rod and the vertical rod can demonstrate front and rear shafts, left and right shafts and upper and lower shafts so as to be convenient to compare with the deflection condition of a mixing shaft, and scale marks on a round frame are convenient to observe the deflection angle of the mixing shaft; the demonstration instrument is adopted to assist the teaching of the table tennis theory, so that the learning interest of students can be improved, and the teaching means is more standard, scientific and convincing. The demonstration instrument has practical significance for improving the teaching effect of the table tennis technical theory.

When the demonstration instrument is used, the bottom plate and the L plate of the demonstration instrument are clamped at the end line of the table tennis table, and the fastening bolt on the L plate is screwed to realize fixation. The round frame is rotated according to the teaching content, the shaft sleeve is fixed by the limiting regulator, and the arrow points the motion direction of the table tennis. The front and rear supporting rods of the demonstration instrument can be demonstrated as longitudinal shafts, the horizontal cross rods can be demonstrated as transverse shafts, and the vertical rods can be demonstrated as vertical shafts. Then, the position of the universal rod is adjusted, and the phenomenon that the ball rotates along the universal rod is demonstrated and explained.

Drawings

FIG. 1 is a schematic perspective view of the present invention;

FIG. 2 is a cross-sectional view taken along line A-A of the sleeve portion of FIG. 1;

FIG. 3 is a cross-sectional view taken along line B-B of the ball portion of FIG. 1;

the device comprises a base plate, a fixing bolt, a base plate, a fixing bolt, a base plate, a fixing base, a fixing bolt, a fixing arrow, a fixing bolt, a fixing base, a fixing base, a fixing base, a fixing bolt, a fixing base, a fixing bolt, a base, a fixing base, a base.

Detailed Description

The present invention will be described in further detail with reference to the following examples:

table tennis cardan shaft demonstration appearance, as shown in figure 1, including the base and fix montant 12 on the base, the base includes the L board 1 of bottom, is fixed with horizontally bottom plate 3 on the L board 1, is fixed with the collet 4 of frustum form on the bottom plate 3, and the lower extreme of montant 12 is connected with collet 4 upper end center fixed perpendicular, is provided with fastening bolt 2 on the L board 1.

The lower part of the vertical rod 12 is hinged with a shaft sleeve 7, as shown in fig. 2, a central hole is arranged in the shaft sleeve 7, two ends of the central hole of the shaft sleeve 7 are hinged with the vertical rod 12 through a large bearing 21, and the upper end and the lower end of the shaft sleeve 7 are fastened with the vertical rod 12 through fastening nuts. The top end of the vertical rod 12 is fixedly connected with a ball cage universal joint 13, a main shaft 14 of the ball cage universal joint 13 is connected with a universal rod 15, and a ball 16 is hinged on the universal rod 15. As shown in FIG. 3, a central through hole is formed in the ball 16, two ends of the central through hole of the ball 16 are hinged to the universal rod 15 through a small bearing 22, and two ends of the central through hole of the ball 16 are provided with fastening nuts.

Two horizontal cross rods 9 are arranged on two sides of the shaft sleeve 7, a horizontal rear supporting rod 11 is arranged at the rear end of the shaft sleeve 7, a horizontal front supporting rod 6 is arranged at the front end of the shaft sleeve 7, and an included angle between each two adjacent horizontal cross rods 9, each horizontal rear supporting rod 11 and each horizontal front supporting rod 6 is 90 degrees. A round rack 10 is sleeved on the two horizontal cross rods 9, the horizontal rear supporting rod 11 and the horizontal front supporting rod 6, the end parts of the two horizontal cross rods 9 and the horizontal rear supporting rod 11 are fixedly connected with the inner side of the round rack 10, the horizontal front supporting rod 6 passes through the round rack 10 and then continues to extend forwards, an arrow 5 is fixed at the front end of the horizontal front supporting rod 6, and scale marks are arranged on the round rack 10.

Be provided with limit adjuster 8 on the axle sleeve 7, limit adjuster 8 includes spring 17, locating pin 18, gland 19 and circle cover 20, and wherein circle cover 20 is fixed on axle sleeve 7 outer wall, is provided with spring 17 in the

circle cover

20, and 20 openings of circle cover are connected with gland 19, and locating pin 18 passes in circle cover 20 and the axle sleeve 7 lateral wall gets into axle sleeve 7, and the interval is provided with a plurality of recesses on the 12 circumferences of montant, and 18 most advanced insert in the recess of locating pin, prevent that the axle sleeve from rotating along the montant.

Example 1: when demonstrating the motion law of the spin-up ball or spin-down ball, the universal rod 15 is adjusted to be parallel to the horizontal cross bar 9, the universal rod 15 is a left and right shaft at the moment, and the ball 16 is rotated to rotate forwards or backwards along the left and right shaft. Then, the demonstration is combined for explanation, and the rotation property of the sphere 16 is an upward rotating sphere or a downward rotating sphere; the ball 16 rotates forward about this axis as an upward spin and rotates backward as a downward spin, based on the player.

Example 2: when demonstrating the motion law of rotating the ball on the left or rotating the ball on the right, the universal rod 15 is adjusted to be in a line with the vertical rod 12, the universal rod 15 is an upper shaft and a lower shaft, and the ball 16 is rotated to rotate along the upper shaft and the lower shaft in the left or right direction. Then, in connection with the demonstration teaching, the sphere 16 rotates along the up-down axis, when the rotating nature of the sphere 16 is a sidespin sphere. Based on the player, the ball 16 rotates left around the axis to turn to a left spin, and rotates right to turn to a right spin.

Example 3: when demonstrating the motion law of clockwise or counterclockwise rotating balls, the universal rod 15 is adjusted to be parallel to the horizontal front supporting rod 6, the universal rod 15 is a front-rear shaft at the moment, and the ball 16 is rotated to rotate along the front-rear shaft in the clockwise or counterclockwise direction. Then, in connection with the demonstration teaching, the sphere 16 rotates along the anteroposterior axis, when the rotating nature of the sphere 16 is either a direct spin or a contra spin. On the player's basis, the ball 16 spins clockwise about this axis as a clockwise spin, and spins counterclockwise about this axis as a counter-spin.

Example 4: when demonstrating the movement law of the rotating ball of the inclined shaft, the universal rod 15 is adjusted to be at a position forming a certain angle with the horizontal front supporting rod 6, the horizontal cross rod 9 and the vertical rod 12, the universal rod 15 is the inclined shaft at the moment, the inclined angle of the inclined shaft is observed according to the scale marks on the round frame 10, and the ball body is rotated to rotate along the inclined shaft. Then, combined with demonstration teaching, in the practice of table tennis, simple spin-up, spin-down, spin-sideways, spin-forward, and spin-reverse are quite rare. And almost all the balls with upward and downward rotation have more or less lateral rotation properties or clockwise and anticlockwise rotation properties, and the balls with lateral rotation also have more or less upward and downward rotation properties or clockwise and anticlockwise rotation properties, such as lateral upward rotation balls, lateral downward rotation balls, lateral clockwise rotation balls and lateral anticlockwise rotation balls. However, in all cases, the rotation axes of these rotary balls are all mixed axes of the three basic rotation axes, which may be called skew axes.

Claims

1. Table tennis cardan shaft demonstrates appearance, including the base and fix montant (12) on the base, its characterized in that: the lower part of the vertical rod (12) is hinged with a shaft sleeve (7), the top end of the vertical rod (12) is fixedly connected with a ball cage universal joint (13), a main shaft (14) of the ball cage universal joint (13) is connected with a universal rod (15), and a ball body (16) is hinged on the universal rod (15); two horizontal cross rods (9) are arranged on two sides of the shaft sleeve (7), a horizontal rear supporting rod (11) is arranged at the rear end of the shaft sleeve (7), a horizontal front supporting rod (6) is arranged at the front end of the shaft sleeve (7), and an included angle of 90 degrees is formed between every two adjacent horizontal cross rods (9), every two adjacent horizontal rear supporting rods (11) and every two adjacent horizontal front supporting rods (6); the round rack is characterized in that a round rack (10) is sleeved on the two horizontal cross rods (9), the horizontal rear supporting rod (11) and the horizontal front supporting rod (6), the end parts of the two horizontal cross rods (9) and the horizontal rear supporting rod (11) are fixedly connected with the inner side of the round rack (10), the horizontal front supporting rod (6) penetrates through the round rack (10) and then continues to extend forwards, an arrow (5) is fixed at the front end of the horizontal front supporting rod (6), and scale marks are arranged on the round rack (10).

2. The table tennis cardan shaft demonstration instrument according to claim 1, wherein: the base comprises an L plate (1) at the bottom end, a horizontal bottom plate (3) is fixed on the L plate (1), a frustum-shaped bottom support (4) is fixed on the bottom plate (3), the lower end of a vertical rod (12) is fixedly and vertically connected with the center of the upper end of the bottom support (4), and a fastening bolt (2) is arranged on the L plate (1).

3. The table tennis cardan shaft demonstration instrument according to claim 1, wherein: the novel bearing is characterized in that a central hole is formed in the shaft sleeve (7), two ends of the central hole of the shaft sleeve (7) are hinged to the vertical rod (12) through large bearings (21), and the upper end and the lower end of the shaft sleeve (7) are fastened to the vertical rod (12) through fastening nuts.

4. The table tennis cardan shaft demonstration instrument according to claim 1, wherein: the ball body (16) is provided with a central through hole, two ends of the central through hole of the ball body (16) are hinged with the universal rod (15) through the small bearing (22), and two ends of the central through hole of the ball body (16) are also provided with fastening nuts.