Device and method for preparing otnu expansion test coal pen by hydraulic one-step forming method

Abstract

The invention relates to a device and method for preparing an Ohnu expansion test coal pen through a hydraulic one-time forming method, and the device comprises a test platform, a fixed support, a die cushion, a forming die, a funnel and a sliding guide plate, and further comprises a hydraulic cylinder support, a hydraulic cylinder and a pressure rod; the forming die is of an axisymmetric semi-opening and closing structure, a hydraulic cylinder drives a pressure rod, and coal powder is pressed into a coal pen according to a pressure value and pressing time which are set in a hydraulic control system in advance. The improved forming die is utilized, a hydraulic mode is adopted, coal powder is added at a time and then pressed into the coal pen at a time, the success rate of coal pen preparation is greatly increased, the test efficiency is greatly improved, and the labor intensity of test operators is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of bituminous coal Oassian dilatometer testing, and in particular to a device and method for preparing an Oassian dilatometer test coal pen by a hydraulic one-step forming method. Background Art

[0002] The Dilatometer test method was first created by Audibert of France in 1926 and later improved by Arnu, so it is usually called the Dilatometer test internationally.

[0003] The Ouss-Almaty dilatometer test is an important method for directly measuring the cohesiveness of bituminous coal. It does not require the addition of any inert substances. Its test index has unparalleled advantages in distinguishing medium and above cohesive coal, especially strong cohesive coal, which can reflect not only the amount of colloid but also the quality of colloid. Therefore, the Ouss-Almaty dilatometer test index is an important index for guiding coal development, production, processing and utilization. In 1953, the Ouss-Almaty dilatometer test was listed as an important index for international coal classification, and in 1986 it was listed as an auxiliary index for China's coal classification GB / T587-1986.

[0004] In 2014, my country issued the "Bituminous Coal Ouaga Dilatometer Test" standard (GB / T5450-2014), which stipulates that in the Ouaga Dilatometer test, the coal pencil must first be prepared using a coal pencil preparation device, which consists of a forming mold and its accessories, a forming striker, a demoulding pressure device and its accessories, and a sample cutter. The steps for making a coal pencil are as follows: First, wipe the forming mold with a cloth brush, and apply a thin layer of wax on the inner wall of the forming mold with a wax stick. Weigh a certain mass of analytical test coal sample, put it in a small evaporating dish, and add a certain amount of water to moisten it. Then place the forming mold on the mold support, put on the upper funnel, use a bull horn spoon to load the coal sample along the funnel until the forming mold is filled, press the striking guide plate horizontally on the funnel, and compact the sample vertically with the striking rod. Place the entire mold under the striker, first strike 4 times with the long strike rod, then add the sample and strike 4 times again, then use the long, medium and short strike rods to strike 2 times each, 4 times each time, for a total of 24 times. Remove the strike guide and funnel, remove the molding die, put the ejection guide on the small-diameter end of the molding die, put the sample tube on the large-diameter section of the molding die, then insert the ejection piston into the ejection guide, then place the entire device in the demoulding press, and rotate the handle to push the coal pencil into the sample tube.

[0005] In the actual operation process, the preparation of coal pencils often encounters problems such as uneven wax coating, weak force in hitting the coal pencil, or difficulty in controlling the amount of coal powder added multiple times, which leads to the coal pencil being unable to be demoulded or breaking. Repeated preparation increases the test intensity and prolongs the test time.

[0006] The "Coal pencil for bituminous coal Oassian dilatometer test and its preparation method and method for improving the repeatability of bituminous coal expansion test" disclosed in the Chinese patent application with publication number CN113607524A, the "Device and method for quickly preparing a coal pencil for bituminous coal Oassian dilatometer test" disclosed in the Chinese patent application with publication number CN 116642743 A, the "A coal pencil forming striker for bituminous coal Oassian test" disclosed in the Chinese utility model patent with publication number CN212932105U, and the "coal pencil striking forming device" disclosed in the Chinese utility model patent with publication number CN215512407U all adopt the coal pencil preparation method specified in GB / T5450-2014, that is, the coal pencil is prepared by using a heavy object to fall and strike the coal powder loaded in the mold. Summary of the invention

[0007] The present invention provides a device and method for preparing an Oerlikon expansion test coal pencil by a hydraulic one-time forming method. By using an improved forming die and a hydraulic method, coal powder is added once and then pressed into a coal pencil at one time, which greatly improves the success rate of coal pencil preparation, greatly improves the test efficiency, and reduces the labor intensity of test operators.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A device for preparing an Oerlikon expansion test coal pencil by a hydraulic one-time forming method, comprising a test platform, a fixed bracket, a die pad, a forming die, a funnel and a sliding guide plate; the fixed bracket is arranged on the test platform, and the die pad, the forming die and the funnel are arranged on the test platform inside the fixed bracket in sequence from bottom to top; the sliding guide plate is slidably connected to the fixed bracket, and a locking mechanism is arranged between the two; the device for preparing an Oerlikon expansion test coal pencil by a hydraulic one-time forming method also comprises a hydraulic cylinder bracket, a hydraulic cylinder and a pressure rod; the hydraulic cylinder bracket is arranged on the fixed bracket; an upper positioning hole is provided in the middle of the top plate of the fixed bracket, and a lower positioning hole is provided in the middle of the sliding guide plate, the lower end of the pressure rod passes through the lower positioning hole and then extends into the coal pencil forming cavity of the forming die, and the upper end of the pressure rod passes through the upper positioning hole; a hydraulic cylinder is arranged directly above the pressure rod, the hydraulic cylinder is arranged on the hydraulic cylinder bracket, and the piston rod of the hydraulic cylinder is arranged vertically downward.

[0010] Furthermore, a device for preparing an Oerlikon expansion test coal pencil by a hydraulic one-time molding method also includes a hydraulic system and a hydraulic control system; the liquid inlet and outlet ends of the hydraulic cylinder are respectively connected to the hydraulic system, the hydraulic system includes a hydraulic pump, and the hydraulic pump is driven by a motor; the control end of the motor is connected to the hydraulic control system.

[0011] Furthermore, the forming mold is an axisymmetric half-open structure, and metal buckles are provided at the two halves of the opening.

[0012] Furthermore, the fixed bracket is composed of a bottom plate, a column and a top plate, and a mold pad positioning groove is arranged on the bottom plate; the sliding guide plate is slidably connected with the column.

[0013] Furthermore, the locking mechanism between the fixed bracket and the sliding guide plate is composed of a plurality of locking bolts, and bolt holes are provided on the outer side of the sliding guide plate at positions corresponding to the columns, and the locking bolts and the bolt holes are arranged in a one-to-one correspondence.

[0014] A method for preparing an Oa expansion test coal pencil by a hydraulic one-step forming method comprises the following steps:

[0015] 1) Open the molding film, apply a layer of wax film on the inner wall of the coal pencil molding cavity of the molding die, and then lock and fix it with a metal buckle, place the molding die in the die pad, and place the funnel on the top of the molding die to form a mold assembly;

[0016] 2) Add the test coal powder into the coal powder forming cavity of the forming die through a funnel, and place the mold assembly after sample loading on the test platform; the piston rod of the hydraulic cylinder is initially in a retracted state;

[0017] 3) The sliding guide plate slides along the column of the fixed bracket to the top of the funnel, presses the mold assembly from above, and then locks the sliding guide plate and the fixed bracket with the locking bolts;

[0018] 4) Insert the lower end of the pressure rod into the funnel through the lower positioning hole on the sliding guide plate; start the hydraulic system to control the piston rod of the hydraulic cylinder to extend downward, and when the piston rod head of the hydraulic cylinder contacts the top surface of the pressure rod, the hydraulic cylinder stops moving and is ready to press the coal pencil;

[0019] 5) Restart the hydraulic system, the piston rod of the hydraulic cylinder pushes the pressure rod downward to apply pressure to the coal powder in the forming die; according to the pressure value and pressing time pre-set in the hydraulic control system, the coal powder is pressed into a coal pencil;

[0020] 6) After the pressing process is completed, the hydraulic control system controls the hydraulic cylinder piston rod to retract upward, lifts the pressure rod, releases the sliding guide plate and moves it upward, and then removes the mold assembly from the fixed bracket;

[0021] 7) Loosen the metal buckle of the forming mold, take out the pressed coal pencil, and cut it according to the set length.

[0022] Furthermore, in the step 5), the pressure value is set to 800-2000N, and the pressing time is 30-50s.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1) By using the improved forming die and hydraulic method, the coal powder is added once and pressed into a coal pencil at one time, which greatly improves the success rate of coal pencil preparation, greatly improves the test efficiency, and reduces the labor intensity of test operators;

[0025] 2) The forming mold adopts an axisymmetric semi-open structure, which makes wax coating, sample loading and coal pencil removal operations simpler and more convenient;

[0026] 3) The coal pencil is pressed and formed in one step by a hydraulic cylinder. The pressure and time during pressing are controlled by a hydraulic control system to ensure that the coal pencil has the same compactness each time, which is beneficial to the repeatability of the test and the accuracy of the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The present invention is a schematic structural diagram of a device for preparing an Oerlikon expansion test coal pencil by a hydraulic one-step forming method.

[0028] In the figure: 1. Die pad 2. Forming die 3. Funnel 4. Sliding guide 5. Fixed bracket 6. Pressure rod 7. Piston rod 8. Hydraulic cylinder 9. Hydraulic cylinder bracket 10. Hydraulic control system 11. Hydraulic pump 12. Motor DETAILED DESCRIPTION

[0029] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings:

[0030] like Figure 1 As shown, the device for preparing the Oerlikon expansion test coal pencil by the hydraulic one-time molding method described in the present invention includes a test platform, a fixed bracket 5, a mold pad 1, a molding die 2, a funnel 3 and a sliding guide plate 4; the fixed bracket 5 is arranged on the test platform, and the mold pad 1, the molding die 2 and the funnel 3 are arranged on the test platform inside the fixed bracket 5 in sequence from bottom to top; the sliding guide plate 4 is slidably connected to the fixed bracket 5, and a locking mechanism is arranged between the two; the device for preparing the Oerlikon expansion test coal pencil by the hydraulic one-time molding method also includes a hydraulic cylinder bracket 9, a hydraulic cylinder 8 and a pressure rod 6; the hydraulic cylinder bracket 9 is arranged on the fixed bracket 5; an upper positioning hole is opened in the middle of the top plate of the fixed bracket 5, and a lower positioning hole is opened in the middle of the sliding guide plate 4, the lower end of the pressure rod 6 passes through the lower positioning hole and then extends into the funnel 3, and the upper end of the pressure rod 6 passes through the upper positioning hole; a hydraulic cylinder 8 is arranged directly above the pressure rod 6, and the hydraulic cylinder 8 is arranged on the hydraulic cylinder bracket 9, and the piston rod 7 of the hydraulic cylinder 8 is arranged vertically downward.

[0031] Furthermore, the device for preparing the Oerlikon expansion test coal pencil by the hydraulic one-time molding method described in the present invention also includes a hydraulic system and a hydraulic control system 10; the liquid inlet and outlet ends of the hydraulic cylinder 8 are respectively connected to the hydraulic system, the hydraulic system includes a hydraulic pump 11, and the hydraulic pump 11 is driven by a motor 12; the control end of the motor 12 is connected to the hydraulic control system 10.

[0032] Furthermore, the forming mold 2 is an axisymmetric half-open structure, and metal buckles are provided at the two halves of the opening.

[0033] Furthermore, the fixed bracket 5 is composed of a bottom plate, a column and a top plate, and a mold pad positioning groove is provided on the bottom plate; the sliding guide plate 4 is slidably connected to the column.

[0034] Furthermore, the locking mechanism between the fixed bracket 5 and the sliding guide plate 4 is composed of a plurality of locking bolts. Bolt holes are provided on the outer side of the sliding guide plate 4 at positions corresponding to the columns, and the locking bolts and the bolt holes are arranged in a one-to-one correspondence.

[0035] The method for preparing an Oerlikon expansion test coal pencil by a hydraulic one-step forming method of the present invention comprises the following steps:

[0036] 1) Open the molding film 2, apply a layer of wax film on the inner wall of the coal pencil molding cavity of the molding die 2, and then lock and fix it with a metal buckle, place the molding die 2 in the mold pad 1, and place the funnel 3 on the top of the molding die 2 to form a mold assembly;

[0037] 2) Add the test coal powder into the coal powder forming cavity of the forming die 2 through the funnel 3, and place the mold assembly after sample loading on the test platform; the piston rod 7 of the hydraulic cylinder 8 is initially in a retracted state;

[0038] 3) The sliding guide plate 4 slides along the column of the fixed bracket 5 to the top of the funnel 3, the mold assembly is pressed from above, and then the sliding guide plate 4 and the fixed bracket 5 are locked and fixed by the locking bolts;

[0039] 4) Insert the lower end of the pressure rod 6 into the funnel 3 through the lower positioning hole on the sliding guide plate 4; start the hydraulic system to control the piston rod 7 of the hydraulic cylinder 8 to extend downward, and when the piston rod 7 of the hydraulic cylinder 8 contacts the top surface of the pressure rod 6, the hydraulic cylinder 8 stops moving and is ready to press the coal pencil;

[0040] 5) Restart the hydraulic system, the piston rod 7 of the hydraulic cylinder 8 pushes the pressure rod 6 downward, and applies pressure to the coal powder in the forming die 2; according to the pressure value and pressing time pre-set in the hydraulic control system 10, the coal powder is pressed into a coal pencil;

[0041] 6) After the pressing process is completed, the hydraulic control system 10 controls the piston rod 7 of the hydraulic cylinder 8 to retract upward, lifts the pressure rod 6, releases the sliding guide plate 4 and moves it upward, and then removes the mold assembly from the fixed bracket 5;

[0042] 7) Loosen the metal buckle of the forming die 2, take out the pressed coal pencil, and cut it according to the set length.

[0043] Furthermore, in the step 5), the pressure value is set to 800-2000N, and the pressing time is 30-50s.

[0044] In order to solve the problem that the preparation process of the coal pencil for the Oerlikon expansion test requires multiple additions of coal powder and multiple striking with a striker, which makes the coal pencil easy to break and difficult to succeed, the present invention provides a device and method for preparing the coal pencil by one-time forming, which does not require multiple additions of coal powder and multiple striking, and the coal pencil can be prepared by one-time hydraulic forming.

[0045] According to GB / 5447-2014 "Method for Determining the Cohesiveness Index of Bituminous Coal", the coal types required for the Oerlikon dilatometer test are classified. First, the cohesiveness index of bituminous coal is determined. According to the G value of the determination result and the classification of coal in GB / T5751-2009 "China Coal Classification Standard", the coal types corresponding to different G values ​​are found, as shown in Table 1.

[0046] Table 1 G value table for each type of coal

[0047]

[0048] For coal types with G below 50, such as lean coal, lean lean coal, and lean coal, the Oa expansion degree is not measured. For coking coal and fat coal with 65<G<85, and coal types with G>85, such as 1 / 3 coking coal, fat coal, and gas fat coal, coal pens are made through different steps.

[0049] For coking coal and fat coal with 65<G<85, according to the sample preparation requirements, the coal particle size is ground to <3mm, and then crushed to pass through a sieve with a mesh diameter of 0.2mm after reaching the air-dried state. Coal samples with a particle size of <0.2mm should conform to the sample particle size distribution shown in Table 2.

[0050] Table 2 Sample particle size distribution

[0051] Particle size / mm composition / % ＜0.20 Composition = 100 ＜0.10 70<Composition≤85 ＜0.06 55<Composition≤70

[0052] In order to more intuitively embody the present invention, the embodiments of the present invention are further described in conjunction with examples. The following examples are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any technical solution that can be obviously obtained by a person skilled in the art within the technical scope disclosed in the present invention, including simple changes or equivalent replacements, is within the protection scope of the present invention.

[0053] [Example 1]

[0054] In this embodiment, the coal type to be tested by the Oerlikon dilatometer is fat coal, G = 70. The process of preparing the coal pencil by the hydraulic one-step forming method is as follows:

[0055] Step 1: According to the sample preparation requirements, the coal is ground to a particle size of less than 3 mm. After reaching the air-dried state, it is crushed until all the coal passes through a sieve with a mesh diameter of 0.2 mm. The sample particle size meets the requirements of the "Oarlberg Dilatometer Test for Bituminous Coal" GB / T5450-2014.

[0056] Step 2: Use Figure 1 The device shown in the figure is for preparing the coal pencil for the Oa expansion test by the hydraulic one-step molding method. A layer of wax film is evenly applied on the inner wall of the coal pencil molding cavity of the molding mold 2, and then the molding molds 2 are put together and locked by metal buckles; the molding mold 2 is placed in the mold pad 1, and the funnel 3 is placed on the molding mold 2, and the bottom of the funnel 3 is connected to the top of the molding mold 2 to ensure that the coal powder in the funnel can flow smoothly into the molding mold 2.

[0057] Step 3: Use a small spoon to add the test coal powder into the funnel. When the coal powder fills the forming mold 2, place the mold assembly (including the mold pad 1, the forming mold 2 and the funnel 3) as a whole on the test platform, and press and fix the mold assembly by sliding the guide plate 4.

[0058] Step 4: Insert the lower end of the pressure rod 6 into the funnel 3 through the lower positioning hole on the sliding guide plate 4.

[0059] Step 5, start the hydraulic system, control the piston rod 7 of the hydraulic cylinder 8 to extend downward, and when the rod head of the piston rod 7 of the hydraulic cylinder 8 contacts the top surface of the pressure rod 6, the hydraulic cylinder 8 stops moving and prepares to press the coal pencil.

[0060] Step 6, restart the hydraulic system, the piston rod 7 of the hydraulic cylinder 8 pushes the pressure rod 6 downward to apply pressure to the coal powder in the forming mold 2; according to the pressure value (1000N) and pressing time (35s) ​​pre-set in the hydraulic control system 10, the coal powder is pressed into a coal pencil.

[0061] Step 7, after the pressing process is completed, the hydraulic control system 10 controls the piston rod 7 of the hydraulic cylinder 8 to retract upward, lifts the pressure rod 6, releases the sliding guide plate 4 and moves it upward, and then removes the mold assembly from the fixed bracket 5.

[0062] Step 8: Loosen the metal buckle of the forming mold 2, take out the pressed coal pencil, and cut it into 60 cm length.

[0063] [Example 2]

[0064] In this embodiment, the coal type to be subjected to the Oerlikon dilatometer test is coking coal mixed with 10% (mass percentage) biomass, G>65. The process of preparing the coal pencil by hydraulic one-step molding method is as follows:

[0065] Step 1: According to the sample preparation requirements, the coal is ground to a particle size of less than 3 mm. After reaching the air-dried state, it is crushed until all the coal passes through a sieve with a mesh diameter of 0.2 mm. The sample particle size meets the requirements of the "Oarlberg Dilatometer Test for Bituminous Coal" GB / T5450-2014.

[0066] Step 2: Use Figure 1 The device shown in the figure is for preparing the coal pencil for the Oa expansion test by the hydraulic one-step molding method. A layer of wax film is evenly applied on the inner wall of the coal pencil molding cavity of the molding mold 2, and then the molding molds 2 are put together and locked by metal buckles; the molding mold 2 is placed in the mold pad 1, and the funnel 3 is placed on the molding mold 2, and the bottom of the funnel 3 is connected to the top of the molding mold 2 to ensure that the coal powder in the funnel can flow smoothly into the molding mold 2.

[0067] Step 3: Use a small spoon to add the test coal powder into the funnel. When the coal powder fills the forming mold 2, place the mold assembly (including the mold pad 1, the forming mold 2 and the funnel 3) as a whole on the test platform, and press and fix the mold assembly by sliding the guide plate 4.

[0068] Step 4: Insert the lower end of the pressure rod 6 into the funnel 3 through the lower positioning hole on the sliding guide plate 4.

[0069] Step 5, start the hydraulic system, control the piston rod 7 of the hydraulic cylinder 8 to extend downward, and when the rod head of the piston rod 7 of the hydraulic cylinder 8 contacts the top surface of the pressure rod 6, the hydraulic cylinder 8 stops moving and prepares to press the coal pencil.

[0070] Step 6, restart the hydraulic system, the piston rod 7 of the hydraulic cylinder 8 pushes the pressure rod 6 downward to apply pressure to the coal powder in the forming mold 2; according to the pressure value (1200N) and pressing time (38s) pre-set in the hydraulic control system 10, the coal powder is pressed into a coal pencil.

[0071] Step 7, after the pressing process is completed, the hydraulic control system 10 controls the piston rod 7 of the hydraulic cylinder 8 to retract upward, lifts the pressure rod 6, releases the sliding guide plate 4 and moves it upward, and then removes the mold assembly from the fixed bracket 5.

[0072] Step 8: Loosen the metal buckle of the forming mold 2, take out the pressed coal pencil, and cut it into 60 cm length.

[0073] [Example 3]

[0074] In this embodiment, the coal type to be subjected to the Oerlikon dilatometer test is coking coal mixed with 20% (mass percentage) biomass, G>65. The process of preparing the coal pencil by the hydraulic one-step molding method is as follows:

[0075] Step 1: According to the sample preparation requirements, the coal is ground to a particle size of less than 3 mm. After reaching the air-dried state, it is crushed until all the coal passes through a sieve with a mesh diameter of 0.2 mm. The sample particle size meets the requirements of the "Oarlberg Dilatometer Test for Bituminous Coal" GB / T5450-2014.

[0076] Step 2: Use Figure 1 The device shown in the figure is for preparing the coal pencil for the Oa expansion test by the hydraulic one-step molding method. A layer of wax film is evenly applied on the inner wall of the coal pencil molding cavity of the molding mold 2, and then the molding molds 2 are put together and locked by metal buckles; the molding mold 2 is placed in the mold pad 1, and the funnel 3 is placed on the molding mold 2, and the bottom of the funnel 3 is connected to the top of the molding mold 2 to ensure that the coal powder in the funnel can flow smoothly into the molding mold 2.

[0077] Step 3: Use a small spoon to add the test coal powder into the funnel. When the coal powder fills the forming mold 2, place the mold assembly (including the mold pad 1, the forming mold 2 and the funnel 3) as a whole on the test platform, and press and fix the mold assembly by sliding the guide plate 4.

[0078] Step 4: Insert the lower end of the pressure rod 6 into the funnel 3 through the lower positioning hole on the sliding guide plate 4.

[0079] Step 5, start the hydraulic system, control the piston rod 7 of the hydraulic cylinder 8 to extend downward, and when the rod head of the piston rod 7 of the hydraulic cylinder 8 contacts the top surface of the pressure rod 6, the hydraulic cylinder 8 stops moving and prepares to press the coal pencil.

[0080] Step 6, restart the hydraulic system, the piston rod 7 of the hydraulic cylinder 8 pushes the pressure rod 6 downward to apply pressure to the coal powder in the forming mold 2; according to the pressure value (1400N) and pressing time (40s) pre-set in the hydraulic control system 10, the coal powder is pressed into a coal pencil.

[0081] Step 7, after the pressing process is completed, the hydraulic control system 10 controls the piston rod 7 of the hydraulic cylinder 8 to retract upward, lifts the pressure rod 6, releases the sliding guide plate 4 and moves it upward, and then removes the mold assembly from the fixed bracket 5.

[0082] Step 8: Loosen the metal buckle of the forming mold 2, take out the pressed coal pencil, and cut it into 60 cm length.

[0083] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A device for preparing an Oa expansion test coal pencil by a hydraulic one-step forming method, comprising a test platform, a fixed bracket, a die pad, a forming die, a funnel and a sliding guide plate; the fixed bracket is arranged on the test platform, and the die pad, the forming die and the funnel are arranged on the test platform inside the fixed bracket in sequence from bottom to top; the sliding guide plate is slidably connected to the fixed bracket, and a locking mechanism is arranged between the two; it is characterized in that, The device for preparing the Oa expansion test coal pencil by the hydraulic one-time forming method also includes a hydraulic cylinder support, a hydraulic cylinder and a pressure rod; the hydraulic cylinder support is arranged on a fixed support; an upper positioning hole is opened in the middle of the top plate of the fixed support, and a lower positioning hole is opened in the middle of the sliding guide plate, the lower end of the pressure rod passes through the lower positioning hole and extends into the funnel, and the upper end of the pressure rod passes through the upper positioning hole; a hydraulic cylinder is arranged directly above the pressure rod, the hydraulic cylinder is arranged on the hydraulic cylinder support, and the piston rod of the hydraulic cylinder is arranged vertically downward.

2. The device for preparing the Oerlikon expansion test pencil by a hydraulic one-step forming method according to claim 1 is characterized in that: It also includes a hydraulic system and a hydraulic control system; the liquid inlet and outlet ends of the hydraulic cylinder are respectively connected to the hydraulic system, the hydraulic system includes a hydraulic pump, and the hydraulic pump is driven by a motor; the control end of the motor is connected to the hydraulic control system.

3. The device for preparing the Oerlikon expansion test pencil by a hydraulic one-step forming method according to claim 1, characterized in that: The forming mold is an axisymmetric half-opening structure, and metal buckles are arranged at the two half openings.

4. The device for preparing the Oerlikon expansion test pencil by a hydraulic one-step forming method according to claim 1, characterized in that: The fixed bracket is composed of a bottom plate, a column and a top plate. The bottom plate is provided with a mold pad positioning groove; and the sliding guide plate is slidably connected with the column.

5. The device for preparing the Oerlikon expansion test pencil by hydraulic one-step forming method according to claim 4 is characterized in that: The locking mechanism between the fixed bracket and the sliding guide plate is composed of a plurality of locking bolts. Bolt holes are provided on the outer side of the sliding guide plate at positions corresponding to the columns, and the locking bolts and the bolt holes are arranged in one-to-one correspondence.

6. A method for preparing an Oerlikon expansion test pencil by a hydraulic one-step forming method, which is realized based on the device for preparing an Oerlikon expansion test pencil by a hydraulic one-step forming method as claimed in any one of claims 1 to 5, characterized in that: The steps include: 1) Open the molding film, apply a layer of wax film on the inner wall of the coal pencil molding cavity of the molding die, and then lock and fix it with a metal buckle, place the molding die in the die pad, and place the funnel on the top of the molding die to form a mold assembly; 2) Add the test coal powder into the coal powder forming cavity of the forming die through a funnel, and place the mold assembly after sample loading on the test platform; the piston rod of the hydraulic cylinder is initially in a retracted state; 3) The sliding guide plate slides along the column of the fixed bracket to the top of the funnel, presses the mold assembly from above, and then locks the sliding guide plate and the fixed bracket with the locking bolts; 4) Insert the lower end of the pressure rod into the funnel through the lower positioning hole on the sliding guide plate; start the hydraulic system to control the piston rod of the hydraulic cylinder to extend downward, and when the piston rod head of the hydraulic cylinder contacts the top surface of the pressure rod, the hydraulic cylinder stops moving and is ready to press the coal pencil; 5) Restart the hydraulic system, the piston rod of the hydraulic cylinder pushes the pressure rod downward to apply pressure to the coal powder in the forming die; according to the pressure value and pressing time pre-set in the hydraulic control system, the coal powder is pressed into a coal pencil; 6) After the pressing process is completed, the hydraulic control system controls the piston rod of the hydraulic cylinder to retract upward, lifts the pressure rod, releases the sliding guide plate and moves it upward, and then removes the mold assembly from the fixed bracket; 7) Loosen the metal buckle of the forming mold, take out the pressed coal pencil, and cut it according to the set length.

7. The method for preparing an Oerlikon expansion test pencil by a hydraulic one-step forming method according to claim 6, characterized in that: In the step 5), the pressure value is set to 800-2000N, and the pressing time is 30-50s.

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