Portable electromagnetic drive nail gun and direct current boost charging system thereof

Abstract

The utility model discloses a portable electromagnetic drive nail gun and a direct current boost charging system thereof. The system at least comprises three modules and three transformers, the energy storage module outputs low-voltage direct current to primary sides of the transformers, electricity on each primary side is independently controlled by a switch of the control module to form chopped waves, and secondary sides of the transformers are connected in series and then are rectified by the rectifier module to be output to a capacitor for charging; the charging process of the capacitor is divided into two stages by taking the rising of the capacitor voltage to the target voltage as a boundary, the transformation configuration of the first transformer and the second transformer at least reaches the target voltage through the series connection of secondary side output voltages of the first transformer and the second transformer, and the transformation configuration of the third transformer is that the secondary side output voltage at least reaches the final charging voltage of the capacitor; a control module is used to switch the transformer for boost charging the capacitor in two phases. According to the portable nail gun, the high charging speed can be guaranteed in the first stage, and the large-voltage charging target of the capacitor can be achieved in the second stage.

Description

Technical Field

[0001] The utility model relates to the technical field of nail guns, in particular to a portable electromagnetic driven nail gun and a direct current boost charging system thereof. Background Art

[0002] A nail gun is a common nailing device, including electromagnetic nail guns, pneumatic nail guns, mechanical nail guns, etc. Since pneumatic nail guns and mechanical nail guns have a small force, they can only drive small nails, while electromagnetic nail guns can provide greater driving force and can drive large nails (50-90mm diameter).

[0003] Patent 201520580802.4 discloses an electromagnetic nail gun, which first converts the direct current of the battery pack into high-frequency alternating current, and then converts it into high-voltage direct current through a transformer to charge the capacitor. After the capacitor is fully charged, the electromagnetic effect is triggered by discharging the coil to drive the nail. However, the size of the transformer is related to the turns ratio and the working power range. The greater the difference in the turns ratio and the larger the working power range, the more iron core materials and winding coils required for the transformer, so the larger the volume. This patent uses only one transformer, and the entire charging process is boosted by the transformer. Since the voltage is directly boosted to the charging voltage of the capacitor, the turns ratio is relatively different, and the working power is also large, resulting in a large volume of the transformer part. In addition, the iron core and coil of the transformer part occupy a certain weight of the nail gun, and the entire nail gun is large in volume and weight, which is not conducive to the portability of the nail gun; in addition, the capacitor is charged to the target voltage through a transformer, and the charging speed is slow. If the speed is to be increased, the target voltage needs to be increased, but the volume and weight of the transformer will become larger and larger. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a portable electromagnetic driven nail gun and a DC boost charging system thereof, which, in addition to ensuring a small size and portability, can not only ensure a high charging speed in the first stage but also achieve a high voltage charging target for the capacitor in the second stage.

[0005] In order to solve the above technical problems, the utility model discloses a DC boost charging system for a portable electromagnetic driven nail gun in the first aspect, wherein the nail gun is configured to impart nailing kinetic energy by discharging a capacitor to a coil, and the DC boost charging system is used to charge the capacitor, wherein:

[0006] The DC boost charging system includes at least a control module, an energy storage module, a rectifier module, a first transformer, a second transformer and a third transformer;

[0007] The energy storage module is configured to output low-voltage direct current to the primary side of each transformer, and the electric energy on each primary side is independently controlled by the switch of the control module to form a chopper. The secondary sides of each transformer are connected in series and then rectified and output by the rectifier module to charge the capacitor;

[0008] The charging process of the capacitor is divided into two stages based on the capacitor voltage being raised to a target voltage. The first transformer and the second transformer are configured to at least reach the target voltage through the series connection of their secondary output voltages. The third transformer is configured to at least reach the final charging voltage of the capacitor through the secondary output voltage.

[0009] The control module is used to control the first transformer and the second transformer to charge the charger together in the first stage, and switch to the third transformer for charging in the second stage.

[0010] As an optional implementation, the low voltage DC is 12-72V.

[0011] As another optional implementation, the energy storage module is formed by high discharge rate batteries connected in series and / or in parallel.

[0012] As another optional implementation, the target voltage is 200-450V.

[0013] As another optional implementation, the final voltage is 450-550V.

[0014] As another optional implementation, the capacitor is formed by connecting a plurality of capacitors in parallel.

[0015] As another optional implementation, the control module uses voltage detection of the capacitor as a condition for the judgment stage, or uses charging time of the capacitor as a condition for the judgment stage.

[0016] As another optional implementation, the capacity of the capacitor is 500-3000 μF, and the rated voltage is 450-600V.

[0017] A second aspect of an embodiment of the utility model discloses a portable electromagnetic driven nail gun, comprising a DC boost charging system as described in the first aspect of an embodiment of the utility model.

[0018] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0019] The embodiment of the utility model designs three transformers to make the capacitor smaller in size and weight, making it easy to carry. The design of two charging stages can not only ensure a higher charging speed in the first stage but also achieve the charging target of a large capacitor voltage in the second stage, which is helpful for driving large nails. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 It is a partial structural schematic diagram of a DC boost charging system of a portable electromagnetic driven nail gun disclosed in an embodiment of the utility model;

[0022] Figure 2 It is a structural schematic diagram of a PWM chip of a DC boost charging system of a portable electromagnetic driven nail gun disclosed in an embodiment of the utility model;

[0023] Figure 3 It is a structural schematic diagram of a control chip of a DC boost charging system of a portable electromagnetic driven nail gun disclosed in an embodiment of the utility model;

[0024] Figure 4 The utility model discloses a PWM chip and a transformer power supply circuit of a control chip. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the solution of the utility model, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0026] Embodiment 1

[0027] See also Figure 1 The present utility model discloses a DC boost charging system for a portable electromagnetically driven nail gun, wherein the nail gun is configured to impart nailing kinetic energy by discharging a capacitor to a coil, and the DC boost charging system is used to charge the capacitor, wherein:

[0028] The DC boost charging system at least includes a control module, an energy storage module, a rectifier module D, a first transformer A, a second transformer B and a third transformer C;

[0029] The energy storage module is configured to output low-voltage direct current to the primary side of each transformer, and the electric energy on each primary side is independently controlled by the switch of the control module to form a chopper. The secondary sides of each transformer are connected in series and then rectified and output by the rectifier module to charge the capacitor;

[0030] The charging process of the capacitor is divided into two stages based on the capacitor voltage being raised to a target voltage. The first transformer and the second transformer are configured to at least reach the target voltage through the series connection of their secondary output voltages. The third transformer is configured to at least reach the final charging voltage of the capacitor through the secondary output voltage.

[0031] The control module is used to control the first transformer and the second transformer to charge the charger together in the first stage, and switch to the third transformer for charging in the second stage.

[0032] For an example, see Figure 1 , Figure 1 The voltage of capacitor C4 in the circuit will drop to about 230V after discharge at the maximum discharge power. A high discharge rate battery or a high discharge rate battery pack is used to output 24V low voltage DC to the primary side of three transformers, and the secondary sides of the three transformers are connected in series. Two of the transformers boost 24V to about 230V, and the turns ratio of each transformer is about 10:100. After being connected in series, the total boost is about 450V. This is the first stage. In this stage, capacitor C4 is charged from 230V to 450V. When the capacitor voltage is low, a higher charging voltage can be used to make the charging current of the capacitor higher, thereby achieving higher charging efficiency at higher charging voltage and charging current. Compared with the existing single transformer boosting method, such as directly boosting from 230V to 550V (turns ratio of about 24:550), the transformer turns ratio difference in this example is smaller. At the same time, the sum of the power of the two transformers in this example is also smaller (output voltage and output current are smaller), so the volume of the single transformer in this example is much smaller in comparison. In the second stage, another transformer boosts 24V to about 550V, with a turns ratio of about 24:550. In this stage, capacitor C4 is charged from 450V to 550V. Compared with the existing single transformer boosting method, such as directly boosting from 230V to 550V, the turns ratio of the existing transformer is equal to or similar to the turns ratio of the transformer in this example. However, since the output current of the transformer in this example is smaller (the more the charge accumulated in the capacitor, the greater the internal resistance), the transformer has smaller power and smaller volume. After transformer design and experimental verification, the sum of the volumes of the above three transformers is reduced by about 50% compared with the volume and weight of the existing single transformer.

[0033] The embodiment of the utility model designs three transformers to make the capacitor smaller in size and weight, making it easy to carry. The design of two charging stages can not only ensure a higher charging speed in the first stage but also achieve the charging target of a large capacitor voltage in the second stage, which is helpful for driving large nails.

[0034] In an optional embodiment, the low voltage DC is 12-72 V. As a power source for a portable nail gun, its size and weight should not affect portability too much, so this embodiment limits its range to a lower value.

[0035] In yet another optional embodiment, the energy storage module is formed by high discharge rate batteries connected in series and / or in parallel.

[0036] In another optional embodiment, the target voltage is 200-450V. When the capacitor voltage is low, a higher charging voltage can be used to make the charging current of the capacitor higher, thereby achieving higher charging efficiency at higher charging voltage and charging current. As the voltage of the capacitor itself increases, the charging efficiency will become lower and lower. The target voltage of this embodiment can be the inflection point of the change of the charging speed of the selected capacitor verified by experiments (the charging speed of the capacitor voltage before the inflection point is within the preset range, and the charging speed drops to outside the preset range after the voltage exceeds the inflection point), thereby ensuring a higher charging speed in the first stage. Compared with directly boosting to the final voltage, the transformer requires less output power, smaller volume and weight.

[0037] In yet another optional embodiment, the final voltage is 450-550 V. The final voltage is the voltage value required for the electromagnetic force capable of driving large nails (50-90 mm in diameter) to provide sufficient driving force.

[0038] In yet another optional embodiment, the capacitor is formed by connecting a plurality of capacitors in parallel; when the capacitor is discharged, the output current of the capacitor is increased to achieve fast discharge.

[0039] In another optional embodiment, the control module uses the voltage detection of the capacitor as a condition for the judgment stage. Specifically, the voltage of the capacitor is monitored in real time, and when the voltage of the capacitor does not reach the target voltage, it is determined to be in the first stage, and when it is found that the voltage of the capacitor reaches the target voltage, it is determined to be in the second stage.

[0040] In another optional embodiment, the control module uses the charging time of the capacitor as a condition for the judgment stage. Specifically, the reference time required for the voltage of the capacitor to reach the target voltage is first determined based on the voltage of the capacitor, and then the reference time is used as a condition for the judgment stage, that is, if the charging time does not reach the reference time, it is determined to be in the first stage, and if it reaches the reference time, it is determined to be in the second stage.

[0041] The control module includes a PWM chip and a control chip. Figure 2 , Figure 3 . Figure 4The transformer power supply circuit for the PWM chip and the control chip transforms the 24V input power supply into 5V and 15V, wherein 15V power is supplied to the PWM chip and 5V power is supplied to the control chip.

[0042] In yet another optional embodiment, the capacity of the capacitor is 500-3000 μF, and the rated voltage is 450-600V.

[0043] Embodiment 2

[0044] The utility model embodiment discloses a portable electromagnetic driven nail gun, comprising the DC boost charging system as described in the first embodiment.

[0045] The contents disclosed in the embodiments of the present invention only disclose the preferred embodiments of the present invention, which are only used to illustrate the technical solutions of the present invention, rather than to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it should be understood by those skilled in the art that the technical solutions described in the aforementioned embodiments can still be modified, or some of the technical features therein can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A DC boost charging system for a portable electromagnetically driven nail gun, wherein the nail gun is configured to impart nailing kinetic energy by discharging a capacitor to a coil, and the DC boost charging system is used to charge the capacitor, characterized in that: The DC boost charging system includes at least a control module, an energy storage module, a rectifier module, a first transformer, a second transformer and a third transformer; The energy storage module is configured to output low-voltage direct current to the primary side of each transformer, and the electric energy on each primary side is independently controlled by the switch of the control module to form a chopper. The secondary sides of each transformer are connected in series and then rectified and output by the rectifier module to charge the capacitor; The charging process of the capacitor is divided into two stages based on the capacitor voltage being raised to a target voltage. The first transformer and the second transformer are configured to at least reach the target voltage through the series connection of their secondary output voltages. The third transformer is configured to at least reach the final charging voltage of the capacitor through the secondary output voltage. The control module is used to control the first transformer and the second transformer to charge the charger together in the first stage, and switch to the third transformer for charging in the second stage.

2. The DC boost charging system according to claim 1, characterized in that: The low voltage direct current is 12-72V.

3. The DC boost charging system according to claim 2, characterized in that: The energy storage module is formed by connecting high discharge rate batteries in series and / or in parallel.

4. The DC boost charging system according to claim 1, characterized in that: The target voltage is 200-450V.

5. The DC boost charging system according to claim 4, characterized in that: The final charging voltage is 450-550V.

6. The DC boost charging system according to claim 1, characterized in that: The capacitor is formed by connecting a plurality of capacitors in parallel.

7. The DC boost charging system according to claim 1, characterized in that: The control module uses the voltage detection of the capacitor as a condition of the judgment phase, or uses the charging time of the capacitor as a condition of the judgment phase.

8. The DC boost charging system according to claim 1, characterized in that: The capacity of the capacitor is 500-3000 μF, and the rated voltage is 450-600V.

9. A portable electromagnetic driven nail gun, characterized in that: Comprising a DC boost charging system as described in any one of claims 1-8.

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