JPH0540594Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> This invention relates to an air pressure switch that detects the state of brake cylinder pressure in a brake system for a railway vehicle.

<Prior art> In general, a pressure switch in a brake system for a railway vehicle detects if a brake cylinder pressure equal to or higher than a set pressure _P1 is not obtained within a set time _T1 after a command signal to apply the brake is issued. The pressure switch is used to detect insufficient braking, which opens the b contact when the brake cylinder pressure exceeds the set pressure _P1 , and the brake cylinder pressure is set within the set time _T2 after the brake is released. In order to detect if the pressure does not release below the set pressure _P2 , a barometric pressure switch for detecting non-relaxation is installed, which opens the A contact, which had been closed until now, when the brake cylinder pressure falls below the set pressure _P2 . It is necessary to provide

An example of the pressure switch for detecting insufficient braking and the pressure switch for detecting non-relaxation is shown in FIGS. 5a and 5b. As shown in Fig. 5a, the air pressure switch for detecting insufficient air pressure is composed of a b contact 2 and a sliding drive part 4, and this b contact 2 is activated when the brake cylinder pressure exceeds the set pressure _P1 . It is opened by section 4.

At the same time as a brake command signal for applying the brake is generated, a check signal flows through the undercheck check line 8 and is input to the on-delay 10 through the b contact 2. As a result, the on-delay 10 starts operating. On-delay 10 setting time T ₁
When the brake cylinder pressure exceeds the set pressure P1, the drive unit 4 opens the b contact ₂ , so the supply of the reference signal to the on-delay 10 is cut off, and the on-delay 10 does not pass current to the relay coil 12a, and the relay Contact 12b remains open. However, if the pressure does not exceed the set pressure P ₁ within the set time T ₁ , when the set time T ₁ has elapsed, the on-delay 10 causes current to flow through the relay coil 12 a, and the relay contact 12 b closes, causing the pressure to rise within the set time T ₁ . It is detected that the brake cylinder pressure has not exceeded the set pressure _P1 .

Further, as shown in Fig. 5b, the pressure switch for detecting non-relaxation is composed of an a contact 6 and the above-mentioned drive unit 4, and the a contact 6 is opened when the brake cylinder pressure is lower than the set pressure _P2 . , set pressure
It is configured to close when the brake cylinder pressure is P2 or _higher . When the brake command signal disappears, a reference signal flows through the non-relaxation reference line 14. When the brake command signal disappears, the brake cylinder pressure is greater than the set pressure _P2 , so
The a-contact 6 is closed by the drive section 4, and the reference signal flows to the on-delay 16 through the closed a-contact 6, thereby activating it. The brake cylinder pressure reaches the set pressure P ₂ within the set time T ₂
When it becomes smaller, the a contact 6 is opened by the drive unit 4, the reference signal to the on-delay 16 is cut off, no current flows to the relay coil 18a, and the relay contact 18b also remains open. However, within the set time _T2 , the brake cylinder pressure decreases to the set pressure _P2 .
If not, after the set time _T2 has elapsed, the on-delay 16 causes current to flow through the relay coil 18a and closes the relay contact 18b. By this,
It is detected that the brake cylinder pressure has not fallen below the set pressure _P2 within the set time _T2 .

In such a barometric pressure switch, pressure detection is performed by the sliding drive part 4, which increases maintenance costs, and for standardization, the a contact 6 and the b contact 2 are connected to the drive part 4. Since it is configured to open and close, there is a problem in that it is large.

There is an air pressure switch shown in FIG. 6 that solves this problem. In the same figure, 2
0 is a pneumatic converter that converts the air pressure of the brake cylinder into a corresponding voltage (brake pressure signal), and the brake pressure signal from this converter 20 is amplified by an amplifier 22 and then passed through a resistor 24. It is supplied to the non-inverting input terminal of comparator 26. A reference voltage corresponding to a set pressure P ₂ set by a variable resistor 28 is supplied to an inverting input terminal of the comparator 26 via a resistor 30 . Therefore, the comparator 26 generates an L level output signal when the amplified brake pressure signal is smaller than the reference voltage, and generates an H level output signal when it is larger. This output signal is
When it is at L level, the transistor 32 is not conductive, no current flows through the relay coil 34a, and the relay contact 34b remains open, and when it is at H level, the transistor 32 is Continuity, relay coil 34a
Current flows through the relay contact 34b, and the relay contact 34b is closed.
Therefore, the relay contact 34b is opened when the brake cylinder pressure is lower than the set pressure _P2 ,
Since it is closed when the contact point is large, it can be used in place of the contact point 6 for detecting non-relaxation shown in FIG. 5b.

The output of amplifier 22 is also provided via resistor 38 to the inverting input terminal of comparator 36 . A reference voltage corresponding to a set pressure P ₁ set by a variable resistor 40 is supplied to the non-inverting input terminal of the comparator 36 via a resistor 42 . Therefore, when the amplified brake pressure signal is smaller than the reference voltage, an H level output signal is generated, and when it is larger, an L level output signal is generated. Since this output signal is supplied to the base of the transistor 44 via the resistor 46, the transistor 44 becomes conductive when the output signal of the comparator 36 is at H level, causing current to flow through the relay coil 48a and closing the relay contact 48b. However, when the output signal of the comparator 36 is at L level, the transistor 44 becomes non-conductive, no current flows through the relay coil 48a, and the contact 48b is opened. Therefore, when the brake cylinder pressure is less than the set pressure _P1 , the relay contact 48b is closed and the brake cylinder pressure is lower than the set pressure _P1.
Since the relay contact 48b is opened when it is larger than , it can be used in place of the contact 2 for detecting shortage in FIG. 5a. In addition, each component within the range surrounded by a dotted line in FIG. 6 is provided on one printed circuit board.

<Problems to be solved by the invention> According to the air pressure switch shown in FIG. 6, a sliding drive part is not required, so maintenance costs are reduced and the switch can be made smaller. Further, since a circuit for detecting shortage and a circuit for detecting non-resolution are provided, standardization can be achieved. However, if this barometric pressure switch is used for detecting shortage, the switch for detecting non-relaxation is wasted. On the other hand, when used for detecting nonresolution, there was a problem in that the material for detecting insufficiency was wasted.

The purpose of this invention is to provide an air pressure switch that solves the above problems.

<Means for Solving the Problems> In order to achieve the above object, this invention includes a brake pressure signal generation section that generates a brake pressure signal that changes according to changes in brake cylinder pressure, and a brake pressure signal generation section that generates a brake pressure signal that changes according to changes in brake cylinder pressure, and a brake pressure signal generation section that generates a brake pressure signal that changes according to changes in brake cylinder pressure. a reference signal generation unit that generates a corresponding reference signal; and an output in a first state when the signal supplied to one input terminal is larger than the signal supplied to the other input terminal, the reference signal generation unit having two input terminals; a comparator unit that generates a signal and generates an output signal in a second state when the signal supplied to the one terminal is smaller than the signal supplied to the other terminal; and a contact that is closed when the output signal of the comparison section is in the first state and opened when the output signal of the comparison section is in the second state. Then, the output signal of the brake pressure signal generation section is supplied to the one terminal, and the reference signal is supplied to the other terminal, and the reference signal is supplied to the one terminal, and the other terminal is supplied with the reference signal. The present invention is characterized in that the brake pressure signal can be changed to a state in which the brake pressure signal is supplied to the terminal.

<Operation> According to this invention, it is possible to arbitrarily change which input terminal the brake pressure signal and reference signal are supplied to the comparison section. For example, if a brake pressure signal is supplied to one input terminal and a reference signal is supplied to the other input terminal, when the brake pressure signal is smaller than the reference signal,
The output of the comparator is in the second state, the contact is opened, and when the brake pressure signal becomes greater than the reference signal, the output of the comparator is in the first state, and the contact is closed. Therefore, in this case, it can be used as an air pressure switch for detecting non-relaxation.

Also, supply the reference voltage to one input terminal,
Assuming that the brake pressure signal is supplied to the other input terminal, when the brake pressure signal is smaller than the reference voltage, the output of the comparator becomes the first output state, the contact is closed, and the brake pressure signal becomes the reference voltage. When it becomes larger than , the output of the comparator becomes the second state and the contact is opened. Therefore, in this state, it can be used as an air pressure switch for detecting shortage.

<Example> In FIG. 1, 50 is a pneumatic converter that converts the air pressure of a brake cylinder (not shown) into a voltage (brake pressure signal) of a corresponding magnitude (brake pressure signal generation). Department). Note that a constant voltage is supplied to the pneumatic converter 50 by a power source 51 as an excitation voltage. The brake pressure signal from the pneumatic converter 50 is transmitted to the amplifier 5.
2. 52a is an output terminal of the amplifier section 52. 54 is a reference voltage generator, which is connected to the power supply 5.
1 voltage is divided by a variable resistor 58 to generate a reference voltage corresponding to a set pressure (reference signal generation section). 58a is a reference voltage generation terminal.

Reference numeral 62 denotes a comparison section, and the terminal 6 is connected to its non-inverting input terminal.
1 and the resistor 64 is larger than the voltage supplied to the inverting input terminal through the terminal 63 and the resistor 66, an H level output signal is generated and supplied to the non-inverting input terminal. When the voltage supplied to the inverting input terminal is smaller than the voltage supplied to the inverting input terminal, an L level output signal is generated.

The output of this comparator 62 is supplied to the base of a transistor 70 via a resistor 68. This transistor 70 becomes conductive when an H level output signal is supplied from the comparator 62, and as a result of being conductive, a current flows through the relay coil 72a and the relay contact 72b is closed. Further, this transistor 70 becomes non-conductive when an L level output is supplied from the comparator 62, so that no current flows through the relay coil 72a and the relay contact 72b is opened.

These amplification section 52, reference voltage generation section 54, comparison section 62, transistor 70, relay coil 72
Each element within the range surrounded by a dashed line in FIG. 1, such as a and relay contact 72b, is constructed on the same printed circuit board 73. As shown in FIG. 2, the output terminal 52a of the amplifier section 52, the reference voltage generation terminal 58a of the reference voltage generation section 54,
The terminals 61 and 63 are led out by a printed pattern on a printed circuit board 73, and are connected to each other by lead wires 74 and 76. For this connection, as shown in FIG. The output terminal 52a of the amplifier section 52 can be connected to the terminal 63 of the comparison section 62 by the lead wire 76, or the output terminal 52a of the amplifier section 52 can be connected to the terminal 63 of the comparison section 62 by the lead wire 74, as shown by the dotted line in FIG. Thus, the reference voltage generation terminal 58a of the reference voltage generation section 54 can be connected to the terminal 61 of the comparison section 62 by the lead wire 76.

When using this voltage switch for non-relaxation detection, as shown in FIG. The reference voltage generating terminal 58a of the reference voltage generating terminal 58a is connected to the terminal 63 of the comparing section 62 through a lead wire 76. In this state, the amplified brake pressure signal is supplied to the non-inverting input terminal of the comparator 62, and the reference voltage is supplied to the inverting input terminal of the comparator 62. Therefore, as shown in FIG. 3, when the brake pressure signal is smaller than the reference voltage, the output of the comparator 62 is at L level and the relay contact 72b is opened, but when the brake pressure signal exceeds the reference voltage, , the output of the comparator 62 becomes H level, and the relay contact 72b is closed. Therefore, it can be used as a pressure switch for detecting non-relaxation.

In addition, when this barometric pressure switch is used for detecting shortage, the amplifying section 5 is connected as shown by the dotted line in FIG.
2 is connected to the terminal 63 of the comparison section 62, and the reference voltage generation terminal 5 of the reference voltage generation section 54 is connected to the terminal 63 of the comparison section 62.
8a is connected to the terminal 61 of the comparing section 62. In this state, the brake pressure signal is supplied to the inverting input terminal of the comparator 62, and the reference voltage is supplied to the non-inverting input terminal of the comparator 62. Therefore, as shown in FIG. 4, when the brake pressure signal is smaller than the reference voltage, the output of the comparator 62 is at H level, and the relay contact 72b is closed. Further, when the brake pressure signal is higher than the reference voltage, the output of the comparator 62 becomes L level, and the relay contact 72b is opened. Therefore, it can be used as a pressure switch for detecting shortage.

Note that the relay contact 72b is connected to an on-delay 76 and a relay coil 78 as shown in FIG. As a result, in the case of detecting a shortage, if the brake cylinder pressure does not rise above the set pressure within a set time, a relay contact (not shown) that controls opening and closing of the relay coil 78 is closed, and a shortage is detected. .
In addition, in the case of non-release detection, if the brake cylinder pressure does not become lower than the set pressure within the set time,
A relay contact whose opening/closing is controlled by a relay coil 78 is closed, and non-relaxation is detected. Note that the set pressure and set time have different values depending on the case of insufficient detection and the case of non-relaxation detection, and are set to values corresponding to each case.

<Effects of the invention> As described above, in the barometric pressure switch according to this invention, the signal supplied to one input terminal of the comparison section is used as the brake pressure signal, and the signal supplied to the other input terminal is used as the reference signal. It is also possible to switch to a state in which the signal supplied to one input terminal is used as the reference signal and the signal supplied to the other input terminal is used as the brake pressure signal. Therefore, this barometric pressure switch can be used both for detecting shortage and for detecting non-relaxation, and there is no need to separately manufacture the atmospheric pressure switch for detecting shortage and the atmospheric pressure switch for detecting non-relaxation, reducing costs. can do. In addition, if multiple barometric pressure switches are required to detect shortages, or if multiple barometric pressure switches are required to detect nonrelaxation, you can immediately respond by preparing multiple barometric pressure switches based on this invention. .

It should be noted that, as with this invention, one example of an air pressure switch that can be used for both insufficient detection and non-release detection is the one shown in FIG. 7. In this case, the amplified brake pressure signal is supplied to the non-inverting input terminal of the comparator 62, and the reference voltage is supplied to the inverting input terminal of the comparator 62, as in the non-relaxing case of the above embodiment.
Therefore, the comparator 62 generates an H level output signal when the brake pressure signal is equal to or higher than the reference voltage, and at this time, the transistor 70 becomes conductive and the relay contact 72
b is closed. Further, when the brake pressure signal is smaller than the reference voltage, the comparator 62 generates an L level output signal, the transistor 70 becomes non-conductive, and the relay contact 72b is opened. Furthermore, a transistor 80 is provided so that it is non-conductive when the transistor 70 is conductive, and is conductive when the transistor 70 is non-conductive.
Therefore, the transistor 80 becomes conductive when the brake pressure signal is smaller than the reference voltage and the comparator 62 generates an L level output, and the relay coil 82
A current is passed through a to close the relay contact 82b.
Further, when the brake pressure signal is higher than the reference voltage and the comparator 62 generates an output signal of H level, the transistor 80 becomes non-conductive, no current flows through the relay coil 82a, and the relay contact 82b is opened. Therefore, relay contact 8 is used for shortage detection.
A relay contact 72b can be used to detect non-relaxation of 2b.

However, in this case, it is necessary to always provide two transistors and two relays, which increases the number of parts used and reduces reliability accordingly. Moreover, it requires a large amount of mounting space, is large in size, and is also expensive. In contrast, this invention requires only one transistor and one relay, which means fewer parts are used, resulting in higher reliability, smaller mounting space, and lower costs.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of one embodiment of the barometric pressure switch according to this invention, Fig. 2 is an explanatory diagram of the main parts of the same embodiment, and Fig. 3 is a diagram showing the same embodiment when used as a barometric switch for non-relaxation detection. A diagram showing the operating state of each part, FIG. 4 is a diagram showing the operating state of each part when the same embodiment is used as a pressure switch for detecting insufficient pressure,
Figures 5a and 5b show an example of a conventional air pressure switch, Figure 6 shows another example of a conventional air pressure switch, and Figure 7 shows another technique for solving the problems of this invention. FIG. 3 is a block diagram of the means. 50... Pneumatic conversion section (brake pressure signal generation section), 54... Reference voltage generation section (reference signal generation section), 62... Comparison section, 72b... Relay contact (contact).

Claims (1)

[Scope of utility model registration request] It has two input terminals: a brake pressure signal generation section that generates a brake pressure signal that changes according to changes in brake cylinder pressure, and a reference signal generation section that generates a reference signal corresponding to a predetermined set pressure. generates an output signal in a first state when the signal supplied to one input terminal is greater than the signal supplied to the other input terminal, and the signal supplied to said one terminal is supplied to said other terminal; a comparator that generates an output signal in a second state when the output signal is smaller than the signal of the comparator, which is closed when the output signal of the comparator is in the first state, and is closed when the output signal of the comparator is in the second state; and a contact that is opened, and the output signal of the brake pressure signal generation section is supplied to the one terminal, and the reference signal is supplied to the other terminal, and the reference signal is supplied to the one terminal. 1. A barometric pressure switch for a railway vehicle, characterized in that it can be changed to a state in which the brake pressure signal is supplied to the other terminal.