Gas isothermal change demonstration device

Abstract

The utility model provides a gas isothermal change demonstration device, which belongs to the technical field of physical experiment equipment and comprises a metering cylinder, a screw rod, a clamping piece and a fixing frame, the clamping piece is slidably connected to the fixing frame and used for clamping the metering cylinder so as to fix the metering cylinder to the fixing frame, a piston is slidably connected in the metering cylinder and connected with a piston rod, and the piston rod is connected with the screw rod. The end part of the piston rod is detachably connected with a connecting seat, the connecting seat is rotatably connected with one end of a screw rod, the screw rod is in threaded connection with the fixed frame, the lower end of the metering cylinder is provided with a connecting pipe, the connecting pipe is respectively connected with a temperature monitoring unit and a gas pressure monitoring unit through a three-way pipe, and the metering cylinder is provided with scales. The influence of hands on the temperature of the air column in the metering cylinder is effectively avoided, the movement of the piston can be effectively controlled, the piston is kept stable during reading, the accuracy of the volume and pressure reading of the air column is improved, the fixed height of the metering cylinder is adjustable, and reading is facilitated for students.

Description

Technical Field

[0001] The utility model relates to the technical field of physical experiment equipment, in particular to a gas isothermal change demonstration device. Background Art

[0002] Exploring the law of isothermal change of gas is a must-do experiment for students. Realizing isothermal change of gas is the prerequisite for the smooth implementation of this experiment, but it is also a major difficulty in experimental operation. In ordinary experimental teaching, teachers use the theory of thermal equilibrium to perform deductive reasoning and derive the conditions for isothermal change of gas. The existing demonstration of the law of isothermal change of gas requires the operator to hold the syringe and push the piston rod to change the volume of air in the syringe. However, during the experiment, pushing the piston too quickly to change the volume of the gas and immediately reading the gas pressure, as well as holding the outer wall of the gas-filled measuring cylinder for a long time when pushing the piston, will cause the air temperature in the measuring cylinder to change. When reading the values ​​of the gas volume and pressure, the piston needs to be kept stationary by hand. However, due to the compression of the volume of the gas in the measuring cylinder, the gas pressure increases, and the hand exerts a large force on the piston rod and piston, which often causes the piston to be unstable due to hand shaking. When the measuring cylinder moves, the volume and pressure of the gas change. The unstable values ​​are not conducive to reading and will cause large accidental errors. For this reason, the applicant has proposed a gas isothermal change demonstration device. Utility Model Content

[0003] The utility model provides a gas isothermal change demonstration device, aiming to solve the above-mentioned problems.

[0004] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0005] A gas isothermal change demonstration device includes a metering cylinder, a screw, a clamping piece and a fixed frame, the clamping piece is slidably connected to the fixed frame, the clamping piece is used to clamp the metering cylinder to fix the metering cylinder on the fixed frame, a piston is slidably connected in the metering cylinder, the piston is connected to a piston rod, the end of the piston rod is detachably connected to a connecting seat, the connecting seat is rotatably connected to one end of the screw, the screw is threadedly connected to the fixed frame, the lower end of the metering cylinder is provided with a connecting pipe, the connecting pipe is respectively connected to a temperature monitoring unit and a gas pressure monitoring unit through a tee pipe, and a scale is provided on the metering cylinder.

[0006] Preferably, the fixing frame includes a fixing rod, a base and a threaded sleeve, one end of the fixing rod is fixed to the base, the free end of the fixing rod is connected to the threaded sleeve through a connecting arm, the threaded sleeve is threadedly connected to the screw rod, and the clamping member is movably arranged on the fixing rod.

[0007] Preferably, the clamping member includes a clamping plate and a movable sleeve, the movable sleeve is slidably connected to the fixed rod, the movable sleeve is connected to the clamping plate, and the clamping plate is used to clamp the metering cylinder.

[0008] Preferably, a first fixing plate a is provided on the clamping plate, and a first fixing plate b is provided on the upper end of the metering cylinder, and the first fixing plate b is fixed to the first fixing plate a by a plurality of bolts a.

[0009] Preferably, the end of the piston rod is connected to a second fixing plate, and the second fixing plate is connected to the connecting seat via a plurality of bolts b.

[0010] Preferably, the end of the screw is connected to a turntable.

[0011] Preferably, a sliding frame is slidably connected to the base, and an elastic support member for supporting the temperature monitoring unit is slidably connected to the sliding frame. The elastic support member includes a support seat and a pressure spring. Connecting rods slidably connected to the sliding frame are provided on both sides of the support seat, and the two ends of the pressure spring are respectively connected to the support seat and the sliding frame.

[0012] Preferably, the sliding frame includes a support plate and two sliding rods, the two ends of the support plate are respectively connected to the two sliding rods, the ends of the two sliding rods are slidably connected to the base, the sliding rod is provided with a sliding groove, and the connecting rod is slidably connected to the sliding groove.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] The utility model provides a gas isothermal change demonstration device, which can clamp and fix a metering cylinder through a clamping piece, and there is no need to hold the metering cylinder by hand, effectively preventing the temperature of the hand from affecting the temperature of the air column in the metering cylinder; according to the needs of students, the height of the metering cylinder on the fixed frame can be slid and adjusted to facilitate students to read; the metering cylinder is respectively connected to the temperature monitoring unit and the gas pressure monitoring unit through a three-way pipe, and a scale is provided on the metering cylinder, so as to obtain the gas volume, temperature and pressure of the air column in the metering cylinder, so as to understand the relationship between air pressure and air volume under gas isothermal conditions; rotating the screw can control the moving speed of the piston in the metering cylinder, and when reading, the piston is kept in a stationary state, and there is no need for students to press the piston rod by hand. When the pressure of the air column in the metering cylinder is too large, it is difficult to control the force of pressing the piston rod by hand, resulting in instability of the piston, and then moving up and down in the metering cylinder, causing errors in reading the volume of the air column in the metering cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the three-dimensional structure of a gas isothermal change demonstration device according to Example 1 of the present utility model;

[0016] Figure 2 This is a schematic diagram of the three-dimensional structure of a gas isothermal change demonstration device according to Example 1 of the present utility model;

[0017] Figure 3 This is a side structural schematic diagram of a gas isothermal change demonstration device according to Example 1 of the present utility model;

[0018] Figure 4 This is a partial cross-sectional structural diagram of a gas isothermal change demonstration device of the present invention;

[0019] Figure 5 This is a schematic diagram of a partial cross-sectional structure of the connection between the connecting pipe, the tee pipe and the temperature monitoring unit of the utility model;

[0020] Figure 6 This is a schematic diagram of the three-dimensional structure of a gas isothermal change demonstration device according to Example 2 of the present utility model;

[0021] Figure 7 This is a partial structural diagram of a gas isothermal change demonstration device according to Example 2 of the present utility model;

[0022] In the figure, 1 is a metering cylinder, 2 is a piston, 3 is a piston rod, 4 is a screw, 5 is a clamping member, 6 is a clamping plate, 7 is a movable sleeve, 8 is a first fixed plate a, 9 is a fixed frame, 10 is a fixed rod, 11 is a base, 12 is a threaded sleeve, 13 is a connecting arm, 14 is a connecting seat, 15 is a connecting pipe, 16 is a tee pipe, 17 is a sealing ring, 18 is a temperature monitoring unit, 19 is a turntable, 20 is a scale, 21 is a first fixed plate b, 22 is a bolt a, 23 is a second fixed plate, 24 is a bolt b, 25 is a sliding frame, 26 is a support plate, 27 is a sliding rod, 28 is a slide groove, 29 is an elastic support member, 30 is a support seat, 31 is a pressure spring, and 32 is a connecting rod. DETAILED DESCRIPTION

[0023] In order to better understand the technical content of the present invention, specific embodiments are provided below, and the present invention is further described in conjunction with the accompanying drawings.

[0024] Example 1

[0025] See also Figures 1 to 5The utility model provides a gas isothermal change demonstration device, including a metering cylinder 1, a screw 4, a clamping member 5 and a fixed frame 9. The clamping member 5 is slidably connected to the fixed frame 9, and the slidable clamping member 5 is located at the height of the fixed frame 9 to drive the clamped metering cylinder 1 to move up and down, which is convenient for students of different heights to read. The clamping member 5 is used to clamp the metering cylinder 1 to fix the metering cylinder 1 on the fixed frame 9. During the experiment, there is no need to hold the metering cylinder 1, which effectively prevents the temperature of the hand from affecting the temperature of the air column in the metering cylinder 1. A piston 2 is slidably connected to the metering cylinder 1, and the piston 2 is connected to a piston rod 3. The piston rod 3 pushes the piston 2 to slide in the metering cylinder 1 to change the volume of the air column in the metering cylinder 1. The end of the piston rod 3 is detachably connected to a connecting seat 14, which is convenient for replacing the metering cylinder 1. The connecting seat 14 and the screw 4 One end is rotatably connected, and the screw 4 is threadedly connected to the fixing frame 9, so that the speed of rotation of the screw 4 can be controlled to allow the piston 2 to move up and down in the metering cylinder 1, and when reading, the piston 2 is kept in a stationary state, and there is no need for students to press the piston rod 3 by hand. When the pressure of the air column in the metering cylinder 1 is too large, it is difficult to control the force of pressing the piston rod 3 by hand, resulting in the piston 2 being unstable and moving up and down in the metering cylinder 1, causing an error in the reading of the volume of the air column in the metering cylinder 1. A connecting pipe 15 is provided at the lower end of the metering cylinder 1, and the connecting pipe 15 is respectively connected to a temperature monitoring unit 18 and a gas pressure monitoring unit (not marked) through a three-way pipe 16. The temperature monitoring unit 18 is a temperature metal probe, and the gas pressure monitoring unit (not marked) is a gas pressure sensor or a pressure gauge. A scale 20 is provided on the metering cylinder 1, which can read the gas volume of the air column in the metering cylinder 1.

[0026] The fixing frame 9 includes a fixing rod 10, a base 11 and a threaded sleeve 12. One end of the fixing rod 10 is fixed to the base 11. The free end of the fixing rod 10 is connected to the threaded sleeve 12 through a connecting arm 13. The threaded sleeve 12 is threadedly connected to the screw 4. The end of the screw 4 is connected to a turntable 19. The clamping member 5 is movably arranged on the fixing rod 10 to fix the metering cylinder 1. At the same time, the threaded sleeve 12 is threadedly connected to the screw 4. When adjusting the volume of the air column gas in the metering cylinder 1, the screw 4 is rotated by the turntable 19. The rotating screw 4 can push the piston rod 3 to drive the piston 2 to move up and down, thereby achieving the effect of adjusting the volume of the air column gas in the metering cylinder 1. At the same time, the screw 4 can effectively stabilize the piston 2 and improve the reading accuracy.

[0027] The clamping member 5 includes a clamping plate 6 and a movable sleeve 7, the movable sleeve 7 is slidably connected to the fixed rod 10, the movable sleeve 7 is connected to the clamping plate 6, the clamping plate 6 is used to clamp the metering cylinder 1, and the height of the clamping plate 6 is movably adjusted to adjust the height of the fixed metering cylinder 1, wherein a first fixed plate a8 is provided on the clamping plate 6, and a first fixed plate b21 is provided on the upper end of the metering cylinder 1, and the first fixed plate b21 is fixed to the first fixed plate a8 by a number of bolts a22, thereby improving the stability of the metering cylinder 1 fixed to the clamping member 5, and the metering cylinder 1 can be fixed to the clamping plate 6 by a number of bolts a22, and it is convenient to disassemble and replace the metering cylinder 1.

[0028] The end of the piston rod 3 is connected to a second fixing plate 23, which is connected to the connecting seat 14 through a plurality of bolts b24. The piston rod 3 can be fixed to the connecting seat 14 and fixed by the bolts b24 for easy disassembly.

[0029] When in use, the clamping plate 6 clamps the metering cylinder 1, and the first fixing plate b21 is located above the first fixing plate a8. The first fixing plate b21 is fixed to the first fixing plate a8 by a number of bolts a22, thereby fixing the metering cylinder 1 to the clamping plate 6. According to the needs of students, the height of the clamping member 5 and the metering cylinder 1 is adjusted by the movable sleeve 7. After the adjustment is completed, the clamping member 5 and the metering cylinder 1 are fixed at the corresponding height by bolts or other fixing methods. The screw rod 4 is rotated to move the connecting seat 14 downward to contact the second fixing plate 23, and the connecting seat 14 is rotated so that the bolt holes on the connecting seat 14 are aligned with the bolt holes on the second fixing plate 23, and the second fixing plate 23 is fixed by the bolts b24. The fixed plate 23 is on the connecting seat 14, and the three-way pipe 16 is connected to the connecting pipe 15 of the metering cylinder 1. The other ends of the three-way pipe 16 are respectively connected to the temperature monitoring unit 18 and the gas pressure monitoring unit (not marked). The screw 4 is rotated, and the screw 4 drives the piston rod 3 to push the piston 2 to move up and down in the metering cylinder 1, changing the gas volume of the air column in the metering cylinder 1. After the piston 2 moves to the corresponding position, the screw 4 is stopped, and the gas volume of the air column is obtained through the scale 20, the temperature of the air column is obtained through the temperature monitoring unit 18, and the gas pressure of the air column is obtained through the gas pressure monitoring unit (not marked), thereby ensuring that the relationship between air pressure and air volume is understood under gas isothermal conditions.

[0030] Example 2

[0031] See also Figures 6 and 7The difference between this embodiment and embodiment 1 is that a sliding frame 25 is slidably connected to the base 11. In the initial state, the sliding frame 25 is located between the fixed rod 10 and the temperature monitoring unit 18. An elastic support member 29 for supporting the temperature monitoring unit 18 is slidably connected to the sliding frame 25. The elastic support member 29 is used to support the temperature monitoring unit 18, effectively reducing the situation where the three-way pipe 16 is pushed away from the connecting pipe 15 when the air column gas pressure in the measuring cylinder 1 is large. During the experiment, the connecting pipe 15 and the three-way pipe 16 are always in a connected state. The three-way pipe 16 is a hard pipe. A sealing ring 17 is provided on the inner wall of the connection of the tee pipe 16, which effectively reduces the probability of air leakage in the metering cylinder 1. The elastic support member 29 includes a support seat 30 and a pressure spring 31. Connecting rods 32 slidably connected to the sliding frame 25 are provided on both sides of the support seat 30. The two ends of the pressure spring 31 are respectively connected to the support seat 30 and the sliding frame 25. When the sliding frame 25 slides to the bottom of the temperature monitoring unit 18, the support seat 30 is pushed upward under the action of the pressure spring 31, and the support seat 30 acts on the temperature monitoring unit 18 to support the temperature monitoring unit 18.

[0032] The sliding frame 25 includes a support plate 26 and two sliding rods 27. The two ends of the support plate 26 are respectively connected to the two sliding rods 27. The ends of the two sliding rods 27 are slidably connected to the base 11. A sliding groove 28 is provided on the sliding rod 27. The connecting rod 32 is slidably connected to the sliding groove 28, which facilitates the up and down sliding of the connecting rod 32, thereby adjusting the height of the support seat 30.

[0033] When it is necessary to support the temperature monitoring unit 18, the index finger and middle finger press the connecting rods 32 on both sides of the support seat 30 respectively, and the connecting rods 32 slide downward along the slide groove 28. The pressure spring 31 is compressed and contracts, so that the support seat 30 is lower than the bottom end of the temperature monitoring unit 18, and then drives the sliding frame 25 to slide downward to the bottom of the temperature monitoring unit 18. When the support seat 30 is located at the temperature monitoring unit 18, the connecting rod 32 is released, and the pressure spring 31 is reset, driving the support seat 30 to move upward and contact with the temperature monitoring unit 18 to support the temperature monitoring unit 18, effectively reducing the probability of the three-way pipe 16 and the connecting pipe 15 being detached when the air column pressure of the metering cylinder 1 is large, so that the three-way pipe 16 and the connecting pipe 15 remain connected.

[0034] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A gas isothermal change demonstration device, characterized by: It includes a metering cylinder, a screw, a clamping piece and a fixed frame, the clamping piece is slidably connected to the fixed frame, the clamping piece is used to clamp the metering cylinder to fix the metering cylinder on the fixed frame, a piston is slidably connected in the metering cylinder, the piston is connected to a piston rod, the end of the piston rod is detachably connected to a connecting seat, the connecting seat is rotatably connected to one end of the screw, the screw is threadedly connected to the fixed frame, a connecting pipe is provided at the lower end of the metering cylinder, the connecting pipe is respectively connected to a temperature monitoring unit and a gas pressure monitoring unit through a tee pipe, and a scale is provided on the metering cylinder.

2. A gas isothermal change demonstration device according to claim 1, characterized in that: The fixing frame includes a fixing rod, a base and a threaded sleeve. One end of the fixing rod is fixed to the base. The free end of the fixing rod is connected to the threaded sleeve through a connecting arm. The threaded sleeve is threadedly connected to the screw rod. The clamping member is movably arranged on the fixing rod.

3. A gas isothermal change demonstration device according to claim 2, characterized in that: The clamping member includes a clamping plate and a movable sleeve, the movable sleeve is slidably connected to the fixed rod, the movable sleeve is connected to the clamping plate, and the clamping plate is used to clamp the metering cylinder.

4. A gas isothermal change demonstration device according to claim 3, characterized in that: The clamping plate is provided with a first fixing plate a, and the upper end of the metering cylinder is provided with a first fixing plate b, and the first fixing plate b is fixed to the first fixing plate a by a plurality of bolts a.

5. A gas isothermal change demonstration device according to claim 1, characterized in that: The end of the piston rod is connected to a second fixing plate, and the second fixing plate is connected to the connecting seat through a plurality of bolts b.

6. A gas isothermal change demonstration device according to claim 1, characterized in that: The end of the screw is connected with a turntable.

7. A gas isothermal change demonstration device according to claim 2, characterized in that: A sliding frame is slidably connected to the base, and an elastic support member for supporting the temperature monitoring unit is slidably connected to the sliding frame. The elastic support member includes a support seat and a pressure spring. Connecting rods slidably connected to the sliding frame are provided on both sides of the support seat, and the two ends of the pressure spring are respectively connected to the support seat and the sliding frame.

8. A gas isothermal change demonstration device according to claim 7, characterized in that: The sliding frame includes a support plate and two sliding rods, the two ends of the support plate are respectively connected to the two sliding rods, the ends of the two sliding rods are slidably connected to the base, the sliding rods are provided with sliding grooves, and the connecting rod is slidably connected to the sliding grooves.

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