An explosion-proof fuel dispenser nozzle

Abstract

The present invention relates to the technical field of human body static electricity release and elimination, in particular to an explosion-proof fuel dispenser nozzle. Its characteristics are as follows: the nozzle pipe of the fuel dispenser nozzle is covered with conductive rubber, and static electricity is released through the conductive rubber when the nozzle pipe contacts the vehicle fuel tank opening, thereby avoiding the generation of static electric sparks. The beneficial effects are as follows: when using this fuel dispenser nozzle, no static electric sparks are generated, and at the same time, no electric shock feeling is generated to people during the process of human body static electricity release.

Description

Technical Field

[0001] The present invention relates to the technical field of eliminating human static electricity, and particularly to an explosion-proof fuel dispenser nozzle. Background Art

[0002] Currently, fuel dispenser nozzles release human static electricity by grounding the handle. If the vehicle has static electricity, static sparks will be triggered when the fuel nozzle contacts the fuel tank opening, posing a safety hazard. Summary of the Invention

[0003] Intrinsic safety: According to GB3836.4 - 201 standards, explosion-proof electrical appliances are divided into types such as flameproof type, increased safety type, and intrinsic safety type. The characteristic of intrinsically safe electrical equipment is that all its circuits are intrinsically safe circuits, that is, the electric sparks and thermal effects generated under normal working conditions or specified fault conditions cannot ignite the specified explosive mixture circuit. That is to say, this type of electrical appliance does not rely on the explosion-proof of the shell and filling material, but the energy of the electric sparks or thermal effects generated by its circuit during normal use or when a fault occurs is less than 0.28 mJ, which is the minimum ignition energy when the gas concentration is 8.5% (the most explosive concentration).

[0004] According to the discharge time constant T = RC, when C is constant, the larger the resistance, the longer the required discharge time, while too small a resistance results in a large discharge power and is prone to generating sparks. Therefore, what needs to be solved in this case is variable resistance discharge.

[0005] The object of the present invention is to eliminate static sparks when the fuel dispenser nozzle contacts the fuel tank opening.

[0006] Considering that ordinary conductive rubber is easily dissolved by gasoline, the conductive rubber in this case can be selected from types of conductive rubber that are insoluble in gasoline, or conductive plastics, conductive phenolic resins, conductive epoxy resins, etc., or generally referred to as sub-conductors.

[0007] The technical solution of the present invention is as follows:

[0008] An explosion-proof fuel dispenser nozzle, comprising a fuel dispenser nozzle body, a nozzle pipe, and a handle, characterized in that: the nozzle pipe of the fuel dispenser nozzle is covered with conductive rubber or a sub-conductor, and static electricity is released through the resistance of the conductive rubber or sub-conductor when the nozzle pipe contacts the vehicle fuel tank opening, thereby avoiding the generation of static sparks.

[0009] The described explosion-proof fuel dispenser nozzle is characterized in that: the conductive rubber or sub-conductor covering the nozzle pipe of the fuel dispenser nozzle includes at least two sections of resistance (201) R1 and (202) R2, R1 > R2. When the nozzle pipe contacts the vehicle fuel tank opening, a single discharge is carried out through the resistance R1 of the conductive rubber section or sub-conductor section. After the nozzle pipe further penetrates into the fuel tank, discharge is carried out through the resistance R2 of the conductive rubber section or sub-conductor section.

[0010] Furthermore, the invention is characterized in that it also includes an nth conductive rubber segment or a sub-conductor segment, which performs n discharges, where n is the number of discharges.

[0011] The explosion-proof refueling gun is characterized in that the resistance value of the conductive rubber or sub-conductor is 1 megohm to 1000 megohm.

[0012] Further, the characteristic is: 200 megaohms ≧ R1 ≧ 50 megaohms, 50 megaohms ≧ R2 ≧ 1 megaohm.

[0013] The explosion-proof refueling gun is characterized in that the handle of the refueling gun is covered with conductive rubber or a subconductor, and when the refueling gun handle is held by hand, static electricity is released through the resistance of the conductive rubber or the subconductor to avoid generating static sparks.

[0014] The explosion-proof refueling gun is characterized in that the resistance value of the conductive rubber or sub-conductor is 1 megohm to 1000 megohm.

[0015] The explosion-proof refueling gun is characterized in that the conductive rubber covering the handle of the refueling gun is a conductive rubber cavity R3, and at least one conductive block is arranged in the conductive rubber cavity. When the hand touches the handle of the refueling gun, discharge is discharged through the resistor R3. After further tightening the handle of the refueling gun, the conductive rubber cavity is squeezed, causing the conductive block and the metal substrate of the handle to collide and form a ground, thereby completely releasing static electricity.

[0016] The explosion-proof refueling gun is characterized in that the conductive block is a low-resistance conductive rubber R4 or a conductor.

[0017] The explosion-proof refueling gun is characterized in that: 200 megaohms ≧ R3 ≧ 50 megaohms, 50 megaohms ≧ R4 ≧ 1 megaohm.

[0018] The explosion-proof refueling gun is characterized in that the conductive rubber covering the nozzle tube of the refueling gun is a comb-shaped structure. When the nozzle tube contacts the vehicle tank port, the discrete comb-shaped resistance is large. After further penetration into the tank, the comb-shaped structure is squeezed and the resistance becomes smaller.

[0019] The beneficial effects of the present invention are: no static electric spark is generated when the refueling gun is used, and no electric shock feeling is generated to a person during the process of static electricity release from the human body. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is the principle diagram of the fuel gun of the present invention.

[0021] Figure 2 This is a further improved implementation scheme of the fuel gun of the present invention.

[0022] Figure 3 This is an embodiment of the present invention in which the conductive rubber is in a comb shape.

[0023] Figure 4 For Figure 2 The equivalent circuit diagram of the handle in the embodiment. Specific implementation manner

[0024] The present invention will be further described below in conjunction with the accompanying drawings and embodiments. 101 is the main body of the fuel dispenser, and 102 is the nozzle pipe of the fuel dispenser. A conductive rubber 103 is covered on the nozzle pipe of the fuel dispenser. When the nozzle pipe contacts the vehicle fuel tank opening, static electricity is released through the conductive rubber 103 to avoid the generation of static sparks. 104 is the conductive rubber covered on the handle, and through this conductive rubber, human body static electricity can be released by the human hand. Considering the concept of static grounding, leakage resistances in the range of 1 megaohm to 1000 megaohms all belong to anti-static materials. In fact, a resistance of a few megaohms is equivalent to direct grounding (zero-resistance grounding is likely to generate static sparks).

[0025] Figure 2 This is an embodiment for further improvement of the fuel dispenser of the present invention. The conductive rubber covered on the nozzle pipe of the fuel dispenser includes conductive rubbers with three resistance values. The resistance of the 201 section is R1, the resistance of the 202 section is R2, and the resistance of the 203 section is R3. The resistances decrease in sequence, that is, R1 > R2 > R3. According to the actual situation, it can be set as: 600 megaohms ≥ R1 ≥ 200 megaohms, 200 megaohms ≥ R2 ≥ 50 megaohms, 10 megaohms ≥ R3 ≥ 1 megaohm. When the nozzle pipe contacts the vehicle fuel tank opening, a primary discharge is carried out through the resistance R1 of the conductive rubber. After the nozzle pipe further penetrates into the fuel tank, a secondary discharge is carried out through the resistance R2. When the nozzle pipe further penetrates into the fuel tank, a tertiary discharge is carried out through the resistance R3. Further, a conductive rubber of the nth section can also be set to carry out n discharges, where n is the number of discharges. The purpose of carrying out multiple discharges is to further reduce the possible electric sparks generated when releasing static electricity. Therefore, the resistance should be set to decrease from large to small (according to the specific situation, it can be selected from large to small in the range of 1 megaohm to 1000 megaohms). For example, if 3 pre-discharges are set, the resistances can be set to 200 megaohms, 50 megaohms, and 1 megaohm. In Figure 1 In the shown embodiment, a conductive rubber 104 is covered on the handle. Through the conductive rubber 104, human body static electricity can be released by the human hand. However, due to the existence of the resistance of the conductive rubber, the human body static electricity cannot be completely released. Therefore Figure 2In an embodiment, conductive rubber cavities 204 and 205 are provided, where 205 is the cavity space of the conductive rubber cavity. At least one conductive block 206 is provided on the conductive rubber cavity 204. When a hand touches the handle of the fuel dispenser, static electricity is discharged through the resistance R1 of the conductive rubber cavity. After further gripping the handle of the fuel dispenser, the conductive rubber cavity is squeezed, causing the conductive block 206 to touch the metal base material of the handle, thus completely releasing the static electricity to the ground. The conductive rubber cavity 204 can be a sealed cavity (more conducive to explosion protection and reset by compressed air), or a non-sealed cavity (reset by rubber elasticity). The conductive block is made of conductive rubber with a low resistance value (the resistance value is less than that of the conductive rubber cavity, and a resistance less than 50 megohms in the field of static electricity can be considered an electrostatic conductor) or a conductor (such as metal). Refer to Figure 4 the equivalent circuit diagram. The working process is as follows:

[0026] ① When a hand touches the conductive block 206, the static electricity of the human body is discharged once through the resistance of the conductive rubber cavity 204. At this time, no static electricity spark will be generated during touching, and the clicking feeling of human body discharging is also avoided. Refer to the equivalent circuit Figure 4 , where R is the resistance of the conductive rubber material.

[0027] The human body resistance is generally 2 kΩ to 20 MΩ, the static electricity of the human body is generally several thousand volts to tens of thousands of volts, the air breakdown field strength is about 30 kV / cm, and the static electricity shock at the fingertip is exactly caused by the breakdown of the air. Assuming that 3000 volts are required to break down 1 mm, taking the human body static electricity voltage of 9000 volts, according to Ohm's law, the voltage distributed to the human body should not exceed 3000 volts, so the resistance is taken as 4 kΩ to 600 MΩ. According to specific tests, taking the conductive rubber resistance as 50 MΩ to 200 MΩ can meet most cases (such as 100 MΩ). The resistance described in this case is the total resistance of the static electricity overcurrent.

[0028] ② When a hand presses the conductive block 206 to squeeze the conductive rubber cavity 204, the conductive block 206 touches the metal base material of the fuel dispenser pipeline, completing the complete release of the human body static electricity. Refer to the equivalent circuit Figure 4 , and the closing of the switch K is equivalent to the contact conduction between the conductive block 206 and the grounded pipeline.

[0029] Furthermore, in the pressing stroke of the conductive rubber cavity, an nth conductive rubber and a conductor can be provided for n times of discharging, where n is the number of pre-discharges. The purpose of pre-discharging is to further reduce the electric shock feeling of people when releasing static electricity. Therefore, the resistance should be set to decrease from large to small (according to specific circumstances, it can be selected from large to small between 1 MΩ and 1000 MΩ). For example, if 3 pre-discharges are set, the resistance can be set to 100 MΩ, 50 MΩ, and 1 MΩ.

[0030] Figure 3This is an embodiment where the conductive rubber of the present invention is comb-shaped. 301 is a comb-shaped conductive rubber strip. When the nozzle pipe contacts the vehicle fuel tank opening, the discrete comb has a relatively large resistance. After further inserting into the fuel tank, the comb structure is squeezed and the resistance becomes smaller.

[0031] In addition, a glow discharge tube can be provided in the electrostatic discharge circuit to display the electrostatic discharge process (under the condition of meeting explosion-proof requirements, such as using an explosion-proof neon bubble).

[0032] The above application modes and rules do not limit the basic features of the method and application of the present invention, nor limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An explosion-proof fuel gun, comprising a fuel gun main body, a nozzle pipe, and a handle, characterized in that: The nozzle tube of the fuel dispenser is covered with conductive rubber, and static electricity is released through the resistance of the conductive rubber when the nozzle tube contacts the vehicle fuel tank opening, thereby avoiding the generation of static sparks; The conductive rubber covered on the nozzle tube of the fuel dispenser is in a comb-like structure. When the nozzle tube contacts the vehicle fuel tank opening, the resistance of the discrete comb-like structure is relatively large. After further penetrating into the fuel tank, the comb-like structure is squeezed and the resistance becomes smaller, realizing variable-resistance discharge; The conductive rubber covered on the handle of the fuel dispenser is a conductive rubber cavity. At least one conductive block is arranged in the conductive rubber cavity. When the hand touches the handle of the fuel dispenser, static electricity is discharged through the resistance R3 of the conductive rubber cavity. After further gripping the handle of the fuel dispenser, the conductive rubber cavity is squeezed, causing the conductive block to touch the metal base material of the handle to form a ground connection, thereby completely releasing static electricity; The conductive block is made of low-resistance conductive rubber, and the resistance R4 of the low-resistance conductive rubber is less than the resistance R3 of the conductive rubber cavity.

2. The explosion-proof fuel dispenser gun according to claim 1, characterized in that: 200 megohms ≥ R3 ≥ 50 megohms, 50 megohms ≥ R4 ≥ 1 megohm.

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